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FOREWORD To assist you in your sales and service activities, this manual explains the main characteristics of the new Lexus LX470, in particular providing a technical explanation of the construction and operation of new mechanisms and new technology used.

Applicable models: UZJ100 series

This manual is divided into 4 sections. 1. Introduction — Exterior appearance and model code. 2. New Model Outline — Explanation of the product to give a general understanding of its features. 3. Technical Description —Technical explanation of the construction and operation of each new system and component. 4. Appendix — Major technical specifications of the vehicle.

CAUTION, NOTICE, REFERENCE and NOTE are used in the following ways: CAUTION

A potentially hazardous situation which could result in injury to people may occur if instructions on what to do or not do are ignored.

NOTICE

Damage to the vehicle or components may occur if instructions on what to do or not do are ignored.

REFERENCE

Explains the theory behind mechanisms and techniques.

NOTE

Notes or comments not included under the above 3 titles.

For detailed service specifications and repair procedures, refer to the following Repair Manuals: Manual Name 1998 LEXUS LX470 Repair Manual 1998 LEXUS LX470 Electrical Wiring Diagram

Pub. No. Vol.1 Vol.2

RM620U1 RM620U2 EWD338U

All information contained herein is the most up-to-date at the time of publication. We reserve the right to make changes without prior notice.

 1998 TOYOTA MOTOR CORPORATION All rights reserved. This book may not be reproduced or copied, in whole or in part, without the written permission of Toyota Motor Corporation. First Printing: Jan. 13, 1998 01–980113–00

EXTERIOR APPEARANCE

155IN01

155IN02

MODEL CODE AND MODEL LINE-UP MODEL CODE

U Z J 1 0 0 L – GN PGK A 1

BASIC MODEL CODE UZJ100: With 2UZ-FE Engine

GEARSHIFT TYPE P: 4-Speed Automatic, Floor

STEERING WHEEL POSITION L: Left-Hand Drive

GRADE G: —

BODY TYPE G: Station Wagon

ENGINE SPECIFICATION K: DOHC and SFI

BACK DOOR TYPE N: Lift-Up Back Door

DESTINATION A: U.S.A. and Canada

MODEL LINE-UP TRANSMISSION

4-Speed Automatic

DESTINATION

ENGINE

BACK DOOR

GRADE

DRIVE TYPE

A343F

U.S.A. and Canada

2UZ-FE

Lift-Up

—

Full-Time 4WD

UZJ100L-GNPGKA

DEVELOPMENT OBJECTIVES To provide the luxury, quality, comfort, and the interior space that are worthy of the Top of SUVs: Improve dynamic performance and quiet operation Improve riding comfort and provide excellent high–speed driving stability Increase interior space

To continue the tradition of the King of 4x4s: Maintain high strength and durability performance Maintain offroad performance

Characteristics

DESIGN Development focused on the themes that are desired on the Lexus LX470: distinctive character, refinement, and sophistication.

EQUIPMENT A full line of equipment is provided in which the high levels of functionality and superior quality that are worthy of a luxury SUV have been integrated.

To enable you to assess the overview of the Lexus LX470 in detail, this chapter describes the changes and the improvements of the new model over those of the previous model by focusing on the following five key points: design, equipment, main mechanisms, safety features, and environmental measures.

MAIN MECHANISMS Equipped with the following features: 4.7–liter V8–cylinder gasoline engine, independent front suspension (IFS), active height control suspension and adaptive variable suspension (AHC & AVS), and anti– lock brake system (ABS).

ENVIRONMENTAL MEASURES Materials that are suited to recycling are used in bumpers, cladding panels and instrument panel, etc.

155MO41

SAFETY FEATURES Equipped with the latest safety features: crash–safety body, SRS airbags, seat belts, head impact protection structure, and ABS.

DESIGN – EXTERIOR – The exterior has been designed with the uniqueness and sophisticated quality that are worthy of the Lexus brand, while maintaining the powerfulness of the Top of SUVs. The overfenders have been discontinued and the body has been widened (+10mm). The tread has been increased (front: +25mm, rear: +15mm) to achieve a wide design that gives a sense of stability.

SIDE DESIGN The clean sweep that extends from the door surface to the optimally proportioned wheel flares, which do not rely on retrofitted overfenders, expresses a sophisticated strength that distinguishes this model from the medium–level SUVs.

155MO01

FRONT DESIGN A unique and dignified front view has been realized through the adoption of the radical and independent four– beam headlights and the reverse trapezoidal shape of the radiator grille. The highbeam headlights are the multi–reflector type and the lowbeam headlights and the foglights are the projector type. The turn–signal lights use amber light bulbs. Clear outer lenses are used for improved looks. Headlights

Radiator Grille

Turn–Signal Light Foglight

155MO02

REAR DESIGN A high–quality and refined rear design is provided by the exclusive, vertical 2–split rear combination lights and the chrome–plated license plate garnish. The large rear combination lights that are well composed and adopt a horizontal theme are exclusive to the Lexus model. A LED type high–mounted stoplight is provided on the exterior of the back door. High–Mounted Stoplight

Rear Combination Light

License Plate Garnish

155MO03

DESIGN – INTERIOR – INTERIOR DESIGN The superbly designed interior space containing hand–crafted genuine wood and leather express the sophisticated elegance of the top of SUVs. The interior length and width have been considerably increased to realize a roomy interior space and luggage area.

155MO04

TRIMS The door trims express a functional beauty that achieves both the ample volume and the powerfulness of a luxury vehicle.

155MO05

INSTRUMENT PANEL Making the best use of the cabin space, the theme form that extends dynamically from the wide center cluster to the console achieves a prestigious space that is worthy of the topmost model. The front console box and the instrument panel have been joined together. In addition, the front console box and the rear console box have adopted an integrated–look shape by eliminating the offset, thus achieving a sense of continuous flow and quality.

155MO06

COMBINATION METER An elegant optitron meter is provided as standard equipment.

155MO07

MAIN EQUIPMENT – EXTERIOR – GLASS UV reduction glass is used for the front door windows to protect the occupants inside from the ultraviolet rays, and privacy glass is used for the remaining windows to improve the air conditioner performance and ensure privacy. Privacy Glass UV Reduction Glass

155MO08

OUTSIDE REARVIEW MIRROR The outside rearview mirrors have been shaped to achieve excellent aerodynamic characteristics. They are equipped with power retraction, heater, and reverse–linked functions to ensure their ease of use.

QUARTER WINDOW The quarter windows are the swing type that open and close electronically.

Outside Rear View Mirror

Quarter Window Switches

Mirror Control Switch

for Left 155MO09

for Right 155MO10

CLADDING PANELS Cladding panels have been provided to achieve a high–quality design with a continuous sweep from the front bumper to the rear bumper. The cladding panels are made of TSOP (The Super Olefin Polymer) to ensure their recyclability.

155MO11

DISC WHEELS Aluminum disc wheels have been designed with uniqueness and high quality exclusively for the Lexus model.

155MO12

NEW EQUIPMENT – INTERIOR – AIR CONDITIONER A dual auto air conditioner system has been provided. An automatic recirculation/fresh–air system that detects exhaust gases has been adopted. This system helps improve the level of comfort in the vehicle interior by preventing the intrusion of the harmful exhaust gases from the vehicles driven ahead.

Air Conditioner Front Control Panel

Air Conditioner Rear Control Panel 155MO13

Air Flow

155MO14

AUDIO SYSTEM A dedicated anomalous radio and 7 speakers are provided as standard equipment to ensure acoustic quality and product appeal. The CD auto changer which can set up to six discs is integrated with the radio.

155MO16

FM Sub Antenna Full–Range Speaker Tweeter Speaker Power Pole Antenna

Woofer Speaker

FM/AM ETR* with Cassette Deck and CD Auto Changer Power Amplifier

*ETR: Electronic Tuner Radio

Full–Range Speaker

Tweeter Speaker

155MO15

NEW EQUIPMENT – INTERIOR – STEERING WHEEL & COLUMN The steering wheel has been designed with a well– defined form that exudes sportiness and dimensionality. A four–spoke, leather–wrapped steering wheel with airbag is provided as standard equipment. A power tilt & telescopic steering wheel with memory is provided to improve ease of use. The ultrasonic motor which is excellent in quiet operation has been adopted. Dimple Portion 155MO17

6 6

42 mm Tilt & Telescopic Switch Tilt Mechanism

Telescopic Mechanism 155MO18

POWER WINDOWS Power windows are provided as standard equipment. To prevent accidents, power windows with one–touch auto–up/down function that includes jam prevention are provided in all the doors as standard equipment. The switches are the pull–up type, and are provided with illumination to enhance their ease of use and visibility. Power Window Switches

155MO19

SEATS

FRONT SEATS

High–quality seats have been achieved by providing a pleasant and distinctive character to the seats and enhancing their seating comfort.

The front seats exude high quality through their comfortable feel, high level holding performance, and powerful and generous form.

The seat covers are made of genuine leather.

155MO20

SECOND-ROW SEAT

155MO21

THIRD-ROW SEAT

Proper support and roominess are provided to ensure comfort on long drives. A 60/40 split configuration is provided to ensure the ease of in–and–out access to the third–row seat.

It is the detachable type, and the floor looks neat and orderly after the seat has been removed. In addition, it does not block rear visibility in the stored state.

The seat comfortable enough to sit three occupants has been realized.

155MO22

155MO23

NEW EQUIPMENT – INTERIOR – STORAGE SPACE Cup holders, storage compartments, and pockets are located in the various areas to improve ease of use. A small–size overhead console for the model with a moon roof and a large–size overhead console for the model without a moon roof are provided as standard equipment. The overhead console has a built–in garage door opener.

1 Storage Compartments 2 Cup Holders 3 Garage Door Opener 4 Storage for Triangular 1

Emergency Marker

5 Storage for First Aid Kit

6 Storage for Tools and Jack

Large–Size Console

Small–Size Console

2 1

5 1 2 2

LH Side 155MO24

MAIN MECHANISMS 2UZ-FE ENGINE It is a newly developed engine that places emphasis on the torque in the practical range (low– to medium– speed range) and the acceleration performance that required in an SUV. This V8–cylinder, 4.7–liter gasoline engine is a high–performance engine that has thoroughly satisfied the engine performance, quiet operation, and fuel economy requirements.

Cross Section Drawing

New 2UZ–FE 8–Cylinder, V–type 4664 (284.5) 172@4800 (230@4800) 434@3400 (320@3400)

Previous 1FZ–FE 6–Cylinder, In–Line 4477 (273.1) 158@4600 (212@4600) 373@3200 (275@3200)

Performance Curve

2UZ–FE Engine (New Model) 1FZ–FE Engine (Previous Model)

(HP) 240 220

kW 180

200 180 160 140

140

Torque

N·m (ft·lbf) 450 330

155MO40

400

300

350

250

300

210

160

120 100

120 100 80

40 20 0

1000 2000 3000 4000 5000 Engine Speed (rpm)

Output

Item Engine Type No. of Cyls. & Arrangement Displacement cm3 (cu in.) Maximum Output kW@rpm (HP@rpm) Maximum Torque N·m@rpm (ft·lbf@rpm)

155MO36

ENGINE IMMOBILISER The engine immobiliser system prevents vehicle theft by comparing the ID code that is stored in the ECM against the ID code that is stored in the ignition key and permits ignition and the injection of fuel if the codes match. System Overview Transponder Key Coil Spark Plugs

Ignition Key Cylinder

Ignition ECM Transponder Chip

Transponder Key Amplifier

Fuel Injection Injectors 155MO25

MAIN MECHANISMS ACTIVE HEIGHT CONTROL SUSPENSION & ADAPTIVE VARIABLE SUSPENSION (AHC & AVS)

In addition to the Independent Front Suspension (IFS), the LX470 is equipped with the new AHC & AVS mechanism to significantly improve its riding comfort and vehicle posture control AHC

Operating the switch to lower the vehicle height quickly allows easy in–and–out access and raising the vehicle height will make it difficult to occur the interference with the off–road surface. By maintaining the vehicle height at a constant level at all times regardless of the loading condition such as the number of occupants, luggage, etc., the suspension strokes are used effectively and stable driving comfort are always ensured. Damping Mode Select Switch 50 mm 40 mm Approx. 10–15 seconds Improved Drivability over Rough Terrain Height Select Switch

40 mm 50 mm Approx. 3–8 seconds.

Improved Ease of In–and–Out Access 155MO26

AVS

Based on the signals received from the various sensors and switches, this mechanism controls the damping force of the suspension to achieve the high levels of both handling stability and riding comfort. Previous Model

Large

New Model (with AHC + AVS)

Small

Passenger–Car like Ease of Driving and Stability Improved Vehicle Posture During Steering 155MO27

INDEPENDENT FRONT SUSPENSION (IFS) An Independent Front Suspension (IFS) system in which both wheels move independently according to the road surface conditions has been adopted for the front wheels. Together with the capability of the AHC & AVS mechanism, this suspension greatly contributes to realizing excellent riding comfort and driving stability.

155MO37

Comparison to the Rigid Type

LX470 (IFS Type)

Rigid Type 155MO28

SAFETY FEATURES CRASH SAFETY BODY This model uses the same ladder–shape frame that is used on the previous model. In addition, the crossmembers have been optimally allocated to ensure an even higher level of crash safety.

Side Rail Axial Compression Portion

The siderail tips are made into axial–compression type collapsible zones to ensure excellent energy–absorption characteristics.

155MO38

SEAT BELTS The driver and front passenger seats are provided with a 3–point ELR seat belt with a pretensioner and force limiter mechanism as standard equipment. Seat belt adjustable anchors that can adjust the shoulder anchor position in 5 steps have been provided as standard equipment for the seat belts for the front seats and the second–row seat.

Item

Front Seat Belt

Second-Row Seat Belt

Third-Row Seat Belt

Outer Center Outer Center Seat Seat Seat Seat

ELR 3-Point Seat Belt

–

NR 2-Point Seat Belt

–

Pretentioner+Force Limiter

–

Adjustable Anchor

–

S: Standard

155MO29

SRS AIRBAG

The SRS airbags that absorb the impact during a collision and help protect the occupants when used in conjunction with the seat belts are provided as standard equipment for the front seat occupants.

155MO35

HEAD IMPACT PROTECTION STRUCTURE The pillar garnish has adopted a head impact protection structure to dampen the impact on the occupants’ head portion. Energy–Absorbing Panel (Roof/Side Inner Panel)

Plastic Ribs 155MO30

ABS (ANTI-LOCK BRAKE SYSTEM) The vehicle is equipped with an ABS system that ensures the excellent handling of the steering and the stability of the vehicle by preventing the wheels from locking during sudden braking or braking on slippery terrain. ABS Equipped Vehicle

The brakes start to operate. Non–ABS Equipped Vehicle

The illustration shows the image of ABS effect. 155MO31

QUIETER OPERATION BODY Silencer, asphalt sheet, and foam material have been effectively allocated in the various areas of the body to improve the vehicle’s quietness. Areas Applied with Silencer

155MO32

Areas Applied with Asphalt Sheet

155MO39

ENVIRONMENTAL MEASURES TSOP (The Super Olefin Polymer), which excels in recyclability, is used as the plastic materials for the areas such as the front and rear bumpers, cladding panels, etc. Also, a hybrid inflator has been adopted in the driver and front passenger airbags to address the environmental concerns associated with the disposal of the airbags.

Rear Bumper

Front Bumper Cladding Panel 155MO33

Front Passenger Airbag

155MO34

LIST OF EQUIPMENT Equipment

Exterior

Interior

275/ 70R16 Tires Bronze Window Glass Bronze UV Reduction (Front Door) + Privacy Side and Back Door Glass Power Swing Rear Quarter Glass Mud Guard (Front + Rear) Side Protection Molding (Cladding Panel) Power Moon Roof Wireless Door Lock Rear Window Wiper Illuminated Entry System Multi–Reflector Highbeam Headlights Projector Lowbeam Headlights Headlight Cleaner Projector Foglights Power Retractable Outside Rearview Mirrors Cruise Control Power Tilt & Telescopic Steering with Memory Leather–Wrapped 4–Spoke Steering Wheel Power Door Lock Power Window Sunvisor with Variable Vanity Mirror Illumination Cup Holders Overhead Console Dual Auto Air Conditioner Power Front Seat with Heater 60/40 Split Second–Row Seat Front–Facing Third–Row Seat for 3 Occupants Memory System (Front Seats, Outside Rearview Mirrors, Steering Column) Genuine Leather Seat Covers Front Seat Belts with Pretensioner & Force Limiter SRS Airbag (for Driver and Front Passenger) Power Outlets (Center Cluster, Rear Quarter, Rear Console) Wire Harness for Trailer Radio with AM/FM/Cassette/CD Changer Garage Door Opener

Model LX470 S S S S S S O S S S S S O (Canada) S S S S S S S S S S S S S S S S S S S S S S S: Standard O: Option

ENGINE — 2UZ-FE ENGINE

ENGINE 2UZ-FE ENGINE DESCRIPTION The 2UZ-FE engine, which has been newly developed to replace the 1FZ-FE engine, is a V8, 4.7-liter, 32-valve DOHC engine. This engine has been developed to realize high performance, quiet operation, and fuel economy. In addition, it has adopted the ETCS-i (Electronic Throttle Control System-intelligent) to ensure excellent controllability of the vehicle and to improve its comfort.

156EG23

156EG24

ENGINE — 2UZ-FE ENGINE

ENGINE SPECIFICATIONS AND PERFORMANCE CURVE Engine

2UZ-FE (LX470)

1FZ-FE (’97 LX450)

No. of Cyls. & Arrangement

8-Cylinder, V Type

6-Cylinder, In-Line

Valve Mechanism

32-Valve, DOHC, Belt & Gear Drive

24-Valve, DOHC, Chain & Gear Drive

Combustion Chamber

Pentroof Type

Manifolds

Cross-Flow

SFI

4664 (284.5)

4477 (273.1)

94.0 84.0 (3.70 3.31)

100.0 95.0 (3.94 3.74)

9.6 : 1

9.0 : 1

Item

Fuel System Displacement

cm3 (cu. in.)

Bore Stroke

mm (in.)

Compression Ratio Max. Output

[SAE-NET]

172 kW @ 4800 rpm (230 HP @ 4800 rpm)

158 kW @ 4600 rpm (212 HP @ 4600 rpm)

Max. Torque

[SAE-NET]

434 N·m @ 3400 rpm (320 ft·lbf @ 3400 rpm)

373 N·m @ 3200 rpm (275 ft·lbf @ 3200 rpm)

Open

3 BTDC

5 BTDC

36 ABDC

40 ATDC

Open

46 BBDC

40 BBDC

3 ATDC

5 ATDC

API SH EC-II, SJ EC or ILSAC

Intake Valve Timing Exhaust

Fuel Octane Number (RON) Oil Grade

(HP) kW 180 240

:2UZ-FE :1FZ-FE

220

160

N·m (ft·lbf) 440 330 420 310 400 290 380 360 270 340 250 320 230 300 210

180

140

160

120

140

100

120

Output

Torque

200

100 80

20 0

0 156EG21

1000

2000 3000 4000 Engine Speed (rpm)

5000

ENGINE — 2UZ-FE ENGINE

FEATURES OF 2UZ-FE ENGINE Features of the 2UZ-FE engine are listed below. System

Features

Engine Proper

An upright intake port has been adopted to improve the intake efficiency. A taper squish configuration has been adopted to improve the combustion efficiency. A steel laminate type cylinder head gasket has been adopted to improve its reliability. An aluminum oil pan that is integrated with stiffeners has been adopted to reduce noise and vibration. The skirt portion of the piston has been changed in shape and applied with resin coating to reduce friction.

Valve Mechanism

Inner shim type valve lifters have been adopted. Large-diameter intake and exhaust valves have been adopted to reduce the intake and exhaust resistance.

Intake and Exhaust System

Fuel System

A long port intake manifold is used to improve the engine’s torque in the low-to mid speed range. A 2-way exhaust control system has been adopted to improve engine performance and to ensure an even quieter operation. 4-hole type fuel injectors have been adopted to improve the atomization of fuel. A quick connector is used to connect the fuel filter and the fuel hose together to improve serviceability. A fuel pump inertia switch, which stops the fuel pump if an extremely strong impact such as that of a collision is detected, has been adopted to realize excellent safety performance.

Ignition System

The DIS (Direct Ignition System) is used to enhance the reliability of the ignition system. Iridium-tipped spark plugs have been adopted to improve ignition.

Engine Control System

ETCS-i has been adopted to realize excellent controllability and comfort of the vehicle. The cruise control system and the engine immobiliser system have been integrated with the ECM.

ENGINE — 2UZ-FE ENGINE

ENGINE PROPER 1. Cylinder Head Cover Lightweight yet high-strength aluminum head covers are used. An adapter has been provided on the left bank cylinder head cover to improve the serviceability when filling the engine oil. The cylinder head cover gaskets have adopted a double-bead cross-sectional construction to improve their reliability. A large V-bank cover has been adopted for improved design effect.

V-Bank Cover

For Right Bank Adaptor Double-Bead Cylinder Head Cover Gasket Cross Section 155EG01 151EG33

For Left Bank

2. Cylinder Head Gasket 3-layer cylinder head gaskets with shims have been adopted to improve reliability and to minimize the deformation of the cylinder bore. This resulted in improved fuel economy and reduced the consumption rate of engine oil and the emission of exhaust gases. Bead plate Inner Plate A

A’

B’

Shim

A – A’ Cross Section Inner Plate Bead plate B – B’ Cross Section 156EG33

ENGINE — 2UZ-FE ENGINE

3. Cylinder Head The cylinder head, which is made of aluminum, has adopted a pentroof-type combustion chamber. The spark plug has been located in the center of the combustion chamber in order to improve the engine’s antiknocking performance. The angle of the intake and exhaust valves is narrowed and set at 21.55° to permit a compact cylinder head. Uplight intake port have been adopted to improve the intake efficiency. A taper squish combustion chamber has been adopted to improve anti-knocking performance and intake efficiency. In addition, engine performance and fuel economy have been improved. Plastic region tightening bolt is used for the cylinder head bolts for good axial tension.

Valve Angle 21.55° Uplight Intake Port Intake Side

Exhaust Side Taper Squish Area 156EG34

156EG35

ENGINE — 2UZ-FE ENGINE

4. Cylinder Block The cylinder block is made of cast iron. The cylinder block has a bank angle of 90°, a bank offset of 21 mm (0.827 in.) and a bore pitch of 105.5 mm (4.15 in.), resulting in a compact block in its length and width even for its displacement. Part of the volute chamber of the water pump is incorporated into the cylinder block to shorten the engine length. Installation bosses of the two knock sensors are located on the inner side of left and right banks. The plastic region tightening bolts are used, for the crankshaft bearing caps. The starter is located inside the V-bank.

Bank Angle 90° Starter Fitting

Volute Chamber

Bore Pitch 105.5 mm (4.15 in.) 156EG36

ENGINE — 2UZ-FE ENGINE

5. Piston The piston is made of aluminum alloy. The piston head portion has adopted a taper squish to improve the fuel combustion efficiency. The piston ring grooves have been treated with alumite coating to improve the piston’s wear resistance.

Tin Plating

Semi floating type piston pins are used. 156EG02

6. Connecting Rod The sintered and forged connecting rod is very rigid and has little weight fluctuation. A weight-adjusting boss is provided at the big end to reduce fluctuation of weight and balance the engine assembly. The connecting rod cap is held by plastic region tightening bolts. The connecting rods for the right and left banks are placed in opposite directions with the outer marks facing the crankshaft. The connecting rod bearing is made of aluminum alloy.

Left Bank Connecting Rod

Right Bank Connecting Rod

Crankshaft Outer Mark

Front

Outer Marks (Projected) Outer Mark Weight Adjusting Boss 156EG03

156EG09

ENGINE — 2UZ-FE ENGINE

7. Crankshaft A crankshaft made of steel, which excels in rigidity and wear resistance, has been adopted. The crankshaft has 5 jounals and 8 counterweights. The crankshaft bearing is made of aluminum alloy. 156EG25

NOTE:

The positions of the crankshaft pins and pistons are illustrated below. The numbers of the crankshaft and the pistons are shown on the right.

Right Bank

Front

Left Bank

No. 8 Cylinder No. 6 Cylinder No. 4 Cylinder No. 2 Cylinder

No. 7 Cylinder No. 5 Cylinder No. 3 Cylinder No. 1 Cylinder Bank Angle 90°

Front TDC

Nos. 1, 2

Nos. 3, 4

Nos. 5, 6

Nos. 7, 8

BDC

Pin Position 156EG10

ENGINE — 2UZ-FE ENGINE

Crankshaft angles and engine strokes (intake, compression, combustion and exhaust) are shown in the table below. The firing order is 1–8–4–3–6–5–7–2.

Ignition

Cylinder Combustion

Exhaust

Intake

Compression

Combustion

Exhaust

No. 1 No. 8 No. 4 No. 3 No. 6 No. 5 No. 7 No. 2 0°

180°

360°

540°

720°

Crankshaft Angle

156EG11

8. Crankshaft Pully The rigidity of the torsional damper rubber has been optimized to reduce noise.

Damper Rubber

156EG37

ENGINE — 2UZ-FE ENGINE

VALVE MECHANISM 1. General Each cylinder has 2 intake valves and 2 exhaust valves. Intake and exhaust efficiency is increased by means of the larger total port areas. The valves are directly opened and closed by 4 camshafts. The intake camshafts are driven by a timing belt, while the exhaust camshafts are driven through gears on the intake camshafts. Exhaust Camshafts Intake Camshafts

Timing Belt

156EG38

2. Camshafts The camshafts are made of cast iron alloy. The cam nose has been chill treated to increase its abrasion resistance. The exhaust camshafts are driven by gears on the intake camshafts. The scissors gear mechanism is used on the exhaust camshaft to control backlash and suppress gear noise. Intake Camshafts Timing Pully

Exhaust Camshafts Scissors Gear Mechanism

156EG39

ENGINE — 2UZ-FE ENGINE

3. Automatic Tensioner The automatic tensioner is made up of a spring and oil damper, and maintains proper timing belt tension at all time. The automatic tensioner suppresses noise generated by the timing belt.

Push Rod Oil Seal

Silicone Oil Check Ball Spring

Automatic Tensioner

156EG12

4. Intake and Exhaust Valve and Valve Lifter Intake and exhaust valves with large-diameter valve face have been adopted to improve the intake and exhaust efficiency. In addition, narrower valve stems have been adopted to reduce the intake and exhaust resistance and for weight reduction. Inner shim type valve adjusting shims, which allow a greater amount of valve lift, have been adopted. Valve lifters made of steel have been adopted. The valve lifter, which has been made lighter and thinner, provides crowning on its side sliding portion to reduce noise and friction.

Camshaft

Crowning

Valve Adjusting Shim

Valve Lifter

Valve 151EG34

ENGINE — 2UZ-FE ENGINE

LUBRICATION SYSTEM 1. General The lubrication circuit is fully pressurized and all oil passes through an oil filter. A trochid gear type oil pump is directly driven by crankshaft. The water-cooled type engine oil cooler is used to lower the oil temperature.

Oil Pump

Oil Cooler

Oil Strainer 156EG40

Oil Filter

MAIN OIL HOLE

RELIEF VALVE

OIL FILTER

BY-PASS HOLE

OIL COOLER

RELIEF VALVE

OIL PUMP

OIL STRAINER

CYLINDER HEAD (FOR LEFT BANK)

EXHAUST CAMSHAFT JOURNALS

INTAKE CAMSHAFT JOURNALS

CRANKSHAFT JOURNALS

CRANKSHAFT PINS

CYLINDER HEAD (FOR RIGHT BANK)

INTAKE CAMSHAFT JOURNALS

EXHAUST CAMSHAFT JOURNALS

CONNECTING ROD

SCISSORS GEAR MECHANISM

OIL PAN

PISTONS

SCISSORS GEAR MECHANISM

ENGINE — 2UZ-FE ENGINE

2. Oil Pan The oil pan is made up of 2 pieces. No. 1 oil pan is made of aluminum alloy and No. 2 oil pan is made of steel sheet. No. 1 oil pan is secured to the cylinder block and the torque converter housing and is increasing rigidity.

Oil Strainer

Baffle Plate

No. 1 Oil Pan

No. 2 Oil Pan

156EG41

ENGINE — 2UZ-FE ENGINE

COOLING SYSTEM 1. General The cooling system is a pressurized, forced-circulation type. A thermostat with a bypass valve is located on the water inlet housing to maintain suitable temperature distribution in the cooling system. An aluminum radiator core is used for weight reduction.

From Heater

Throttle Body

To Heater

Thermostat

Oil Cooler

156EG42

Throttle Valve Thermostat Thermostat Radiator

Water Pump

Oil Cooler 156EG43

Heater

Heater Valve

ENGINE — 2UZ-FE ENGINE

2. Water Pump The water pump has two volute chambers, and circulates coolant uniformly to the left and right banks of the cylinder block. The water pump is driven by the back of the timing belt. The rotor is made of resin.

From Water Inlet Housing Rotor

Rotor Pulley

Volute Chambers 156EG13

156EG14

3. Coupling Fan A 3-stage temperature-controlled coupling fan is used. It rotates at lower speeds when the engine is started to minimize the fan noise.

ENGINE — 2UZ-FE ENGINE

INTAKE AND EXHAUST SYSTEM 1. Throttle Body The adoption of the ETCS-i has realized excellent throttle control. The ISC system and cruise control system are controlled comprehensively by the ETCS-i. Thus, the IAC valve has been discontinued. A thermostat is installed in the throttle body. The thermostat uses the thermal expansion of the wax to open and close the valve to shut off the flow of warm coolant when the coolant temperature is high in the throttle body’s warm coolant passage. This prevents the throttle body temperature from rising more than the needed level, thus restraining the rise in the intake air temperature. Wax

Valve

To Throttle Body

From Water Outlet

Thermostat

150EG21 147EG24

Thermostat

2. Intake Manifold The low-to mid-speed range torque has been improved by increasing the length of the intake manifold port.

Right Bank Passage

Left Bank Passage

Front 156EG44

ENGINE — 2UZ-FE ENGINE

3. Intake Manifold Gasket A heat-barrier gasket has been adopted for use between the cylinder head and the intake manifold. This gasket, which restrains the heat transfer from the cylinder head to the intake manifold, helps restrain the intake air temperature and improve the charging efficiency. The construction of the gasket consists of resin that is sandwiched between metal gaskets. Resin

Metal Gasket

151EG69

Cross Section 144EG04

4. Exhaust Manifold The exhaust manifolds are made of stainless steel for weight reduction.

Right Bank Exhaust Manifold

Gaskets

156EG04

Left Bank Exhaust Manifold

ENGINE — 2UZ-FE ENGINE

5. Exhaust Pipe General The exhaust pipe is made of stainless steel for improved rust resistance. A clamp type joint is used to join the center pipe and tail pipe to realize weight reduction. A 2-way exhaust control system has been adopted to improve engine performance and to ensure an even quieter operation. Sub Muffler Main Muffler

TWCs

Clamp Type Joint

156EG05

Clamp

Gasket

Exhaust Pipe Connecting Exhaust Pipe 156EG06

ENGINE — 2UZ-FE ENGINE

2-Way Exhaust Control System A 2-way exhaust control system is used. This system reduces the back pressure by opening and closing a variable valve that is enclosed in the main muffler, thus varying the exhaust gas passage. The valve opens steplessly in accordance with the operating condition of the engine, thus enabling a quieter operation at lower engine speeds, and reducing back pressure at higher engine speeds. 1) Construction The control valve is enclosed in the main muffler. When the exhaust gas pressure overcomes the spring pressure, the control valve opens steplessly in accordance with the exhaust gas pressure.

Spring

Valve

156EG01

2) Operation a. When Control Valve is Closed (low engine speed) Since the pressure in the main muffler is low, the control valve is closed. Hence exhaust gas does not pass the bypass passage, and exhaust noise is decreased by the main muffler. b. When Control Valve is Open (middle to high engine speed) The valve opens more as the engine speed and the back pressure in the muffler increase. This allows a large volume of exhaust gas to pass the bypass passage, thereby substantially decreasing the back pressure.

Control Valve (Closes)

Control Valve (Open) Bypass

Exhaust Gas Control Valve Closed

156EG07

Exhaust Gas

156EG08

Control Valve Open

ENGINE — 2UZ-FE ENGINE

FUEL SYSTEM 1. Fuel Pump Inertia Switch General A fuel pump inertia switch, which stops the fuel pump if the vehicle is involved in a violent collision, has been adopted to minimize fuel leakage. The fuel pump inertia switch maintains a circuit between the ECM and the fuel pump ECU, and if a collision is detected, it cuts off the circuit to the fuel pump ECU. By taking the ease of its operation into consideration, the fuel pump inertia switch has been located in the vicinity of the instrument panel. Reset Switch

Fuel Pump Inertia Switch

Fuel Pump Inertia Switch 156EG19

156EG22

System Diagram EFI Main Relay +B

Contact Point

FP+ Fuel Pump ECU

Link

Fuel Pump FP– FPC

Ball Fuel Pump Inertia Switch

ECM Cross Section 156EG18

156EG20

ENGINE — 2UZ-FE ENGINE

50 Construction and Operation

The fuel pump inertia switch consists of a ball that detects a collision, link, contact point, and reset switch. When the acceleration that is generated during a collision of the vehicle exceeds a predetermined value, the ball moves, the link moves downward, and the contact point opens. As a result, the circuit to the fuel pump ECU is cut off. Acceleration Link

Contact Point (OFF)

Contact Point (ON)

Ball Normal

NOTE:

156EG45

Movement 156EG46

Detecting a Collision

In the event that the fuel pump inertia switch has tripped, and the switch must be reinstated, push up the reset switch for 1 second or longer.

2. Injector A compact 4-hole type injector has been adopted to improve the atomization of fuel.

3. Quick Connector

156EG15

A quick connector is used to connect the fuel filter and the fuel house together to improve serviceability.

Fuel Hose

Quick Connector

Fuel Filter

156EG27

ENGINE — 2UZ-FE ENGINE

IGNITION SYSTEM 1. General A DIS (Direct Ignition System) has been adopted in the 2UZ-FE engine. The DIS improves the ignition timing accuracy, reduces high-voltage loss, and enhances the overall reliability of the ignition system by eliminating the distributor. The DIS in 2UZ-FE engine is an independent ignition system which has one ignition coil for each cylinder.

ECM Camshaft Position Sensor

Crankshaft Position Sensor

Various Sensors

Ignition Coil (with Igniter)

IGT1

No. 1 Cylinder

IGT2

No. 2 Cylinder

IGT3

No. 3 Cylinder

IGT4

No. 4 Cylinder

IGT5

No. 5 Cylinder

IGT6

No. 6 Cylinder

IGT7

No. 7 Cylinder

IGT8 IGF1 IGF2

No. 8 Cylinder

151EG05

2. Ignition Coil The DIS provides 8 ignition coils, one for each cylinder. The spark plug caps, which provide contact to the spark plugs, are integrated with an ignition coil. Also, an igniter is enclosed to simplify the system.

Igniter

Secondary Coil

Iron Core

Primary Coil

Plug Cap

Ignition Coil Cross Section

156EG16

ENGINE — 2UZ-FE ENGINE

3. Spark Plug Iridium-tipped spark plugs have been adopted. Their center electrode is made of iridium, which excels in wear resistance. As a result, the center electrode is made with a smaller diameter and improved the ignition performance.

Recommended Spark Plugs

Iridium Tip 0.7 mm (0.028 in.) Platinum Tip

151EG39

DENSO NGK

SK20R11 IFR6A11

Plug Gap

1.0 – 1.1 mm (0.039 – 0.043 in.)

ENGINE — 2UZ-FE ENGINE

SERPENTINE BELT DRIVE SYSTEM 1. General The serpentine belt drive system drives accessory components with a single V-ribbed belt. It reduces the overall engine length, weight and number of engine parts. An automatic tensioner eliminates the need for tension adjustment.

Belt Idler Idler Pulley for Automatic Tensioner

Cooling Fan Pulley

Power Steering Pump Pulley

Air Conditioning Compressor Pulley

Generator Pulley

Crankshaft Pulley 156EG47

2. Automatic Tensioner The tension of the V-ribbed belt is properly maintained by the torsion spring that is enclosed in the automatic tensioner.

Spring

Rotation Direction Bracket

Arm

Bracket

Idler Pulley Shaft Spring Force

Idler Pulley

Spring B

Cross Section

156EG28

A: Fixed to the Arm B: Fixed to the Bracket

156EG29

ENGINE — 2UZ-FE ENGINE

ENGINE CONTROL SYSTEM 1. General In addition to the SFI (Sequential Multiport Fuel Injection) system and the ESA (Electronic Spark Advance) system, the ETCS-i (Electronic Throttle Control System-intelligent) has been adopted in the engine control system to realize excellent vehicle maneuverability and comfort. Also, the cruise control system and the engine immobiliser system have been integrated in the ECM. The engine control system for the 2UZ-FE engine has following system. System

Outline

SFI Sequential Multiport Fuel Injection

An L-type SFI system directly detects the intake air volume with a hot-wire type mass air flow meter. The fuel injection system is a sequential multiport fuel injection system.

ESA Electronic Spark Advance

Ignition timing is determined by the ECM based on signals from various sensors. Corrects ignition timing in response to engine knocking. The torque control correction during gear shifting has been used to minimize the shift shock. 2 knock sensors are used to further improve knock detection.

ETCS-i Electronic Throttle Control System-intelligent Fuel Pump Control Oxygen Sensor Heater Control Air Conditioning Cut-Off Control Evaporative Emission Control Engine Immobiliser

Diagnosis

Fail-Safe

Optimally controls the throttle valve opening in accordance with the amount of the accelerator pedal effort, and the conditions of the engine and the vehicle, and comprehensively controls the ISC, and cruise control. Under light engine loads, pump speed is low to reduce electric power loss. Maintains the temperature of the oxygen sensor at an appropriate level to increase accuracy of detection of the oxygen concentration in the exhaust gas. By controlling the air conditioning compressor ON or OFF in accordance with the engine condition, drivability is maintained. The ECM controls the purge flow of evaporative emissions (HC) in the charcoal canister in accordance with engine conditions. Prohibits fuel delivery and ignition if an attempt is made to start the engine with an invalid ignition key. When the ECM detects a malfunction, the ECM diagnoses and memorizes the failed section. The diagnosis system includes a function that detects a malfunction in the evaporative emission control system. When the ECM detects a malfunction, the ECM stops or controls the engine according to the data already stored in the memory.

ENGINE — 2UZ-FE ENGINE

2. Construction The configuration of the engine control system in the 2UZ-FE engine is shown in the following chart. SENSORS MASS AIR FLOW METER

ACTUATORS VG

SFI #10

CRANKSHAFT POSITION SENSOR

Engine Speed Signal Crankshaft Angle Signal CAMSHAFT POSITION SENSOR

#20 #30 #40 #50 #60 #70 #80

Crankshaft Angle Signal THROTTLE POSITION SENSOR

Throttle Position Signal ACCELERATOR PEDAL POSITION SENSOR

Accelerator Pedal Position Signal ENGINE COOLANT TEMP. SENSOR

INTAKE AIR TEMP. SENSOR HEATED OXYGEN SENSOR (Bank 1, Sensor 1) HEATED OXYGEN SENSOR (Bank 2, Sensor 1) HEATED OXYGEN SENSOR (Bank 1, Sensor 2) HEATED OXYGEN SENSOR (Bank 2, Sensor 2)

KNOCK SENSORS VEHICLE SPEED SENSOR IGNITION SWITCH Starting Signal (ST Terminal) Ignition Signal (IG Terminal) PARK/NEUTRAL POSITION SWITCH

Neutral Start Signal Shift Lever Position Signal AIR CONDITIONING ECU A/C Switch Signal

VTA VTA2 VPA VPA2

IGT1,4,6,7

THW

IGF1

THA

No. 1 INJECTOR No. 2 INJECTOR No. 3 INJECTOR No. 4 INJECTOR No. 5 INJECTOR No. 6 INJECTOR No. 7 INJECTOR No. 8 INJECTOR

ESA IGNITION COIL with IGNITER Nos. 1, 4, 6 and 7

IGT2,3,5,8

ECM

IGF2

IGNITION COIL with IGNITER Nos. 2, 3, 5 and 8

OXL1 SPARK PLUGS SPARK PLUGS Nos. 2, 3, 5 and 8 Nos. 1, 4, 6 and 7

OXR1 OXL2 OXR2

ETCS-i KNKL KNKR SPD

M+,M– CL+,CL–

THROTTLE CONTROL MOTOR MAGNETIC CLUTCH

STA IGSW FPC NSW R,D,2,L

A/C

FUEL PUMP CONTROL FUEL PUMP ECU

FUEL PUMP

AIR CONDITIONING CONTROL ACT

AIR CONDITIONING ECU

THWO (Continued)

ENGINE — 2UZ-FE ENGINE

ELS

THILLIGHT RELAY

OXYGEN SENSOR HEATER CONTROL

HTL BLOWER MOTOR RELAY

ELS2 HTR ELS3

AHC MOTOR RELAY

HTL2 HTR2

ELS4

ABS RELAY

HEATED OXYGEN SENSOR HEATER (Bank 1, Sensor 1) HEATED OXYGEN SENSOR HEATER (Bank 2, Sensor 1) HEATED OXYGEN SENSOR HEATER (Bank 1, Sensor 2) HEATED OXYGEN SENSOR HEATER (Bank 2, Sensor 2)

STP

STOP LIGHT SWITCH

EVAP CONTROL PRG

VAPOR PRESSURE SENSOR

PTNK

VAPOR PRESSURE CONTROL

TXCT RXCK CODE

TRANSPONDER KEY AMPLIFIER

TPC

IMLD UNLOCK WARNING SWITCH DATA LINK CONNECTOR 1

DATA LINK CONNECTOR 3

KSW

MREL

SIL

+B EFI MAIN RELAY

VSV

BATT, BM BATTERY

VSV

THEFT DETERRENT INDICATOR LIGHT

EFI MAIN RELAY

MALFUNCTION INDICATOR LAMP

ENGINE — 2UZ-FE ENGINE

3. Engine Control System Diagram Ignition Switch

VSV for Vapor Pressure Sensor

Fuel Pump ECU

Vapor Pressure Sensor

Fuel Filter

Intake Air Temp. Sensor

Mass Air Flow Meter Fuel Pump

Charcoal Canister

Accelerator pedal Position Sensor

Throttle Control Motor

VSV (for EVAP)

Throttle Position Sensor Ignition Coil (with Igniter)

Injector Injector

Camshaft Position Sensor

Ignition Coil (with Igniter)

*1 *2

*2 TWC

Knock Sensor

TWC

Knock Sensor

*2 *2

Crankshaft Position Sensor

ECM Starter

MIL

Air Conditioner

DLC1 Vehicle Speed Sensor

Battery DLC3

156EG17

Park/Neutral Position Sensor *1: Engine Coolant Temp. Sensor *2: Heated Oxygen Sensor

Ignition Coil (with Igniter)

ECM

Park/Neutral Position Sensor

Throttle Position Sensor Fuel Pump ECU DLC1

Accelerator Pedal Position Sensor

DLC3

Engine Coolant Temp. Sensor

Vapor Pressure Sensor Heated Oxygen Sensor (Bank 1, Sensor 2)

Throttle Control Motor Camshaft Position Sensor Crankshaft Position Sensor

VSV (for Vapor Pressure Sensor) Knock Sensors Heated Oxygen Sensor (Bank 1, Sensor 1) Heated Oxygen Sensor (Bank 2, Sensor 1) 156EG31

ENGINE — 2UZ-FE ENGINE

Mass Air Flow Meter

Injector

Heated Oxygen Sensor (Bank 2, Sensor 2)

4. Layout of Components

VSV (for EVAP)

ENGINE — 2UZ-FE ENGINE

5. Main Components of Engine Control System General The main components of the 2UZ-FE engine control system are as follows: Components Mass Air Flow Meter

Outline Hot-Wire Type

Crankshaft Position Sensor Camshaft Position Sensor Throttle Position Sensor

Pick-Up Coil Type, 1 Pick-Up Coil Type, 1 Linear Type, 2

Accelerator Pedal Position Sensor Knock Sensor

Oxygen Sensor

Injector

Linear Type, 2 Built-In Piezoelectric Type, 2 Heated Oxygen Sensor (Bank 1, Sensor 1) (Bank 2, Sensor 1) (Bank 1, Sensor 2) (Bank 2, Sensor 2) 4-Hole Type

Mass Air Flow Meter The 2UZ-FE engine adopts the hot-wire type mass air flow meter designed for direct electrical measurement of the intake air mass flow. This mass air flow meter offers superior measuring precision and its plastic housing is shaped for minimal flow resistance. It has the following features: Compact and lightweight The pressure loss caused by this sensor is small and offers only slight intake air flow resistance. Superior response and measuring accuracy Ability to measure a wide airflow range Having no mechanical functions, it offers a superior durability.

Hot Wire Intake Air Temp. Sensor

140EG45

ENGINE — 2UZ-FE ENGINE

60 Crankshaft Position Sensor

The crankshaft position sensor is mounted of the timing chain cover as illustrated below. The timing rotor is integrated with the crankshaft pulley. The rotor’s teeth are spaced 10° apart, according to crankshaft angle, but since there are 2 teeth missing, as illustrated below, there is a total of 34 teeth. Accordingly, the ECM can detect the crankshaft angle in addition to the crankshaft speed.

Timing Rotor

Crankshaft Position Sensor 151EG18

Camshaft Position Sensor The camshaft position sensor is mounted on the left bank cylinder head. To detect the camshaft position, a protrusion that is provided on the timing pulley is used to generate 1 pulse for every 2 revolutions of the crankshaft.

Timing Rotor

Crankshaft Position Sensor

156EG26

ENGINE — 2UZ-FE ENGINE

6. ETCS-i (Electronic Throttle Control System-intelligent) General The ETCS-i system, which realizes excellent throttle control in all the operating ranges, has been adopted. In the conventional throttle body, the throttle valve opening is determined invariably by the amount of the accelerator pedal effort. In contrast, the ETCS-i uses the ECM to calculate the optimal throttle valve opening that is appropriate for the respective driving condition and uses a throttle control motor to control the opening. The ETCS-i controls the ISC (Idle Speed Control) system and the cruise control system. A duplicate system is provided to ensure a high level of reliability, and the system shuts off in case of an abnormal condition. Even when the system is shut off, the accelerator pedal can be used to operate the vehicle in the limp mode.

Accelerator Pedal Position Sensor

Throttle Valve Throttle Position Sensor Throttle Control Motor Magnetic Clutch

ECM

150EG71

ENGINE — 2UZ-FE ENGINE

62 Construction

Limp Mode Lever Throttle Valve

Throttle Position Sensor

Accelerator Pedal Position Sensor Throttle Control Motor

Magnetic Clutch 156EG30

1) Accelerator Pedal Position Sensor The accelerator pedal position sensor, which is mounted on the throttle body, is integrated with the throttle lever, which is connected to the cable that extends from the accelerator pedal. The accelerator pedal position sensor converts the amount of accelerator pedal effort into two types of electrical signals with distinct output characteristics. The signals are then input into the ECM.

Output Voltage

Close Open

E2 VPA2 VPA

V 5 VPA2

VPA 0

Open

150EG40

150EG39

Accelerator Pedal Depressed Angle 2) Throttle Position Sensor The throttle position sensor converts the throttle valve opening into an electrical signal and inputs into the ECM. The output characteristics are the same as those of the accelerator pedal position sensor. 3) Throttle Control Motor A DC motor with excellent response and minimal power consumption is used for the throttle control motor. The ECM performs the duty ratio control of the direction and the amperage of the current that flows to the throttle control motor in order to regulate the opening of the throttle valve.

ENGINE — 2UZ-FE ENGINE

4) Magnetic Clutch Ordinarily, the magnetic clutch engages the clutch to enable the throttle control motor to open and close the throttle valve. In case that a malfunction occurs in the system, this clutch is disengaged to prevent the throttle control motor to open and close the throttle valve. Operation The ECM drives the throttle control motor by determining the target throttle valve opening in accordance with the respective operating condition. 1) Non-Linear Control 2) Idle Speed Control 3) Cruise Control 1) Non-Linear Control Controls the throttle to an optimal throttle valve opening that is appropriate for the driving condition such as the amount of the accelerator pedal effort and the engine speed in order to realize excellent throttle control and comfort in all operating ranges. Control Examples During Acceleration and Deceleration

↑

: With Control : No Control

Vehicle’s Longitudinal G 0 Throttle Valve Opening Angle

↑

0 Ignition Timing

↑ 0 Time → 150EG37

2) Idle Speed Control Previously, IAC valve was used to perform idle speed control such as fast idle during cold operating conditions and idle-up. In conjunction with the adoption of the ETCS-i, idle speed control is now performed by the throttle control motor, which controls the throttle valve opening.

ENGINE — 2UZ-FE ENGINE

64 3) Cruise Control

Previously, the vehicle speed was controlled by the cruise control actuator, which opened and closed the throttle valve. Along with the adoption of the ETCS-i, the vehicle speed is now controlled by the throttle control motor, which controls the throttle valve. Fail-Safe If an abnormal condition occurs with the ETCS-i, the MIL illuminates to alert the driver. At the same time, the current to the throttle control motor and magnetic clutch are cut off in order not to operate the ETCS-i. This enables the return spring to close the throttle valve. Even in this situation, the accelerator pedal can be used to operate the limp mode lever, which operates the throttle valve to enable the vehicle to be driven in the limp mode.

Limp Mode Lever

Open

Throttle Position Sensor

Throttle Control Motor Throttle Valve

Magnetic Clutch

Accelerator Pedal Position Sensor

150EG42

Diagnosis The diagnostic trouble codes can be output via DLC3 to an OBD-II scan tool or a hand-held tester. For details, refer to the 1998 Lexus LX470 Repair Manual (Pub. No. RM620U).

ENGINE — 2UZ-FE ENGINE

7. Fuel Pump Control The fuel pump speed control has adopted a fuel pump ECU to execute 3-step fuel pump speed control. System Diagram

FPC Signal

EFI Main Relay

5V Hi 0V

FPC 8.2 ms Fuel FP+ Pump ECU

ECM

Fuel Pump Speed

5V Mid

Fuel Pump

Battery

0V 4.1 ms

5V Low

FP–

Stop

0V 152EG11

152EG12

8. Engine Immobiliser System The engine immobiliser system has been designed to prevent the vehicle from being stolen. This system uses a ECM that stores the ID code of the authorized ignition key. If an attempt is made to start the engine using an unauthorized key, the ECM prohibit fuel delivery and ignition, effectively disabling the engine.

CHASSIS — A343F AUTOMATIC TRANSMISSION

CHASSIS A343F AUTOMATIC TRANSMISSION DESCRIPTION As in the previous model, the A343F automatic transmission is used on the new model. However, the followings are changed; In conjunction with the adoption of the 2UZ-FE engine, the torque converter clutch and the planetary gear unit have been redesigned to accommodate the high power output. The ECM regulates the solenoid valve SLT to control the line pressure. An O/D direct clutch speed sensor has been adopted to detect the input shaft speed in order to realize smooth shift characteristics.

155CH01

Specifications Model Transmission Type Engine Type Item 1st

New A343F

Previous A343F

2UZ-FE 2.804

1FZ-FE

2nd

1.531

3rd

1.000

4th (Overdrive)

0.753

Reverse

2.393

12.0 (12.7, 10.6)

11.7 (12.4, 10.3)

ATF D-II or DEXRON® III (DEXRON® II)

Gear Ratio

Fluid Capacity Liters (US qts, Imp. qts) Fluid Type

CHASSIS — A343F AUTOMATIC TRANSMISSION

TORQUE CONVERTER CLUTCH AND PLANETARY GEAR UNIT The following items have been modified to accommodate the high performance 2UZ-FE engine. The shape of the turbine blades in the torque converter clutch has been optimized. The rear planetary gears have been strengthened by changing from the 4-pinion to 5-pinion configuration. Torque Converter Clutch Model Transmission Type Engine Type Item Converter Type Stall Torque Ratio Nominal Diameter

New

A343F 2UZ-FE

A343F 1FZ-FE

3-Element, 1-Step, 2-Phase, with Lock-Up Mechanism 1.800

272 (10.7)

mm (in.)

Planetary Gear Unit

C0 C1 C2

Model Transmission Type Engine Type Item OD Direct Clutch Forward Clutch No. of Discs Direct Clutch

B0 B1 B2 B3 F0 F1 F2

OD Brake 2nd Coast Brake 2nd Brake 1st & Reverse Brake OD One-Way Clutch No. 1 One-Way Clutch No. 2 One-Way Clutch

Front Planetary Gear

Rear Planetary Gear

OD Planetary Gear

No. of Discs Band Width

mm (in.)

No of Discs No.

No. of Sprags No. of Sun Gear Teeth No. of Pinion Gear Teeth No. of Ring Gear Teeth No. of Sun Gear Teeth No. of Pinion Gear Teeth No. of Ring Gear Teeth No. of Sun Gear Teeth No. of Pinion Gear Teeth No. of Ring Gear Teeth

New

A343F

2UZ-FE

1FZ-FE

2 7 5

6 4

5 40 (1.57) 5 7 24 22 28 42 19 79 33 23 79 31 33 95

CHASSIS — A343F AUTOMATIC TRANSMISSION

ELECTRONIC CONTROL SYSTEM 1. General Based on the A343F of the previous model, the electronic control system of the new model’s A343F automatic transmission has newly adopted the line pressure control using a linear solenoid valve and the O/D direct clutch speed sensor that detects the transmission’s input shaft speed. The electronic control system of the new model’s A343F and the previous model’s A343F are compared below. New

A343F

The optimum shift pattern is selected from 2 shift patterns in the ECM by the pattern select switch. The ECM sends current to the solenoid valve No. 1 and/or No. 2 based on signals from each sensor and shifts the gear.

Lock-Up Timing Control

The optimum lock-up pattern is selected from 2 lock-up patterns in the ECM by the pattern select switch. The ECM sends current to the solenoid valve SL based on signals from each sensor and engages or disengages the lock-up clutch.

Line Pressure Control

Based on the throttle opening angle, the ECM sends a signal to solenoid valve SLT to generate line pressure according to the engine output, to effect a smooth gear shift change.

—

“N” to “D” Squat Control

When the shift lever is shifted from “N” to “D” range, the gear is temporarily shifted to OD and then to 1st to reduce vehicle squat.

Engine Torque Control

Retards the engine ignition timing temporarily to improve shift feeling during up or down shifting.

2nd Start System

Enabling the vehicle to take off in the 2nd gear and thus make it easy to take off on snowy, sandy or muddy terrain.

SelfDiagnosis

Causes the malfunction indicator lamp to turns on to inform the driver when the electrical circuit malfunctions.

Fail-Safe

Controls other normally operating components, permitting continued driving when malfunctions occur in the electrical circuit.

System

Function

Shift Timing Control

CHASSIS — A343F AUTOMATIC TRANSMISSION

2. Construction The configuration of the electronic control system in the new model’s A343F is as shown in the following chart. ACTUATORS

SENSORS MASS AIR FLOW METER

CRANKSHAFT POSITION SENSOR

Engine Speed Signal Crankshaft Angle Signal CAMSHAFT POSITION SENSOR

Throttle Position Signal

SOLENOID VALVE NO. 2

SOLENOID VALVE SL

Crankshaft Angle Signal THROTTLE POSITION SENSOR

SOLENOID VALVE NO. 1

SLT+ SLT– VTA VTA2

SOLENOID VALVE SLT

ETCS-i M+, M– THROTTLE CONTROL MOTOR

ACCELERATOR PEDAL POSITION SENSOR

Accelerator Pedal Position Signal PATTERN SELECT SWITCH PARK/NEUTRAL POSITION SWITCH TRANSFER NEUTRAL POSITION SWITCH

CL+,CL–

VPA VPA2

MAGNETIC CLUTCH

PWR SNWI

IGT1~8

IGNITERS

NSW R,D,2,L TFN

ESA

ECM

IGF1, 2

IGNITION COILS SPARK PLUGS

L4 POSITION SWITCH O/D SWITCH

L4 OD2

MALFUNCTION INDICATOR LAMP

NO. 1 VEHICLE SPEED SENSOR OD2 COMBINATION METER NO. 2 VEHICLE SPEED SENSOR O/D DIRECT CLUTCH SPEED SENSOR

STOP LIGHT SWITCH

SPD SP2

O/D OFF INDICATOR LIGHT

SNWL

2nd START INDICATOR LIGHT

OILW

FLUID TEMP. WARNING LIGHT

PWR

POWER INDICATOR LIGHT

NC0 STP THW

ENGINE COOLANT TEMP. SENSOR FLUID TEMP. SENSOR

OIL

SIL

DATA LINK CONNECTOR 3

CHASSIS — A343F AUTOMATIC TRANSMISSION

3. Construction and Operation of Main Components Solenoid Valve SLT

Solenoid Coil Sleeve

Valve

155CH02

Hydraulic Pressure

In order to provide a hydraulic pressure that is in proportion to the current that flows to the solenoid coil, the solenoid valve SLT linearly controls the line pressure based on the signals it receives from the ECM.

Current

155CH03

O/D Direct Clutch Speed Sensor The O/D direct clutch speed sensor is fitted to the transmission case to detect revolution of the transmission input shaft. The sensor rotor is fitted to the O/D direct clutch drum.

O/D Direct Clutch Drum Sensor Rotor

O/D Direct Clutch Speed Sensor 155CH39

CHASSIS — A343F AUTOMATIC TRANSMISSION

4. Function of ECM Line Pressure Control

Hydraulic Pressure

The previous mechanical control, which consisted of a throttle cable, cam, and throttle valve, has been changed to an electronic control system that uses a solenoid valve SLT. In order to obtain a predetermined line pressure characteristic according to the throttle position sensor (VTA) signal, the ECM activates the solenoid valve SLT to regulate the throttle pressure. This makes it possible for the primary regulator valve to precisely and minutely control the line pressure, in accordance with the engine output, and thus realize smoother shift characteristics. And also, the ECM detects the speed of the transmission input shaft to determine whether or not the transmission is shifting properly in order to ensure the smooth engagement of the clutch. To ensure the optimal speed changes in the transmission input shaft, the ECM controls the solenoid valve SLT to finely regulate the line pressure.

Throttle Pressure

Input Shaft Speed

Current

Solenoid Control Current

ECM

Voltage

Time

O/D Direct Clutch Speed Sensor

Throttle Position Sensor

Line Pressure

Throttle Angle

Line Pressure

Solenoid Valve SLT

Throttle Angle

Primary Regulator Valve

Pump

155CH04

CHASSIS — HF2A TRANSFER

HF2A TRANSFER DESCRIPTION The new model has adopted an HF2A type full-time 2-speed transfer, which integrates a center differential with a differential lock mechanism. The basic construction and operation of the transfer are the same as those of the previous HF2AV transfer, from which the viscous coupling type LSD has been excluded.

155CH46

Specifications Model Transfer Type Item

New

HF2A

HF2AV

Idler Gear

High Speed Range

1.000

Low Speed Range

2.488

—

Viscous Coupling

1.3 (1.4, 1.1)

1.7 (1.8, 1.5)

Oil Viscosity

SAE 75W-90

Oil Grade

API GL-4 or GL-5

Reduction Gear Type Gear Ratio LSD Oil Capacity

Liters (US qts, lmp.qts)

CHASSIS — PROPELLER SHAFT AND DIFFERENTIAL

PROPELLER SHAFT DESCRIPTION As in the previous model, both front and rear propeller shafts have adopted the 2-joint type propeller shaft with a center sliding mechanism.

DIFFERENTIAL DESCRIPTION A front differential that supports the independent front suspension has been adopted. A 9.5-inch ring gear has been adopted in the rear differential. Also, an LSD or differential lock mechanism is available as an option.

155CH47

155CH48

Front Differential

Rear Differential

Specifications Differential Item Ring Gear Size Reduction Gear Ratio Number of Differential Pinions Oil Capacity

in.

Liters (US qts, Imp. qts)

Oil Viscosity Oil Grade *1 With differential lock mechanism *2 Temperatures above – 18°C (0°F) *3 Temperatures below – 18°C (0°F)

Front

Rear

8” 4.300 2

9.5” 4

1.7 (1.8, 1.4)

3.3 (3.5, 2.9) 3.2 (3.4, 2.8)*1

SAE90*2 SAE 80W or 80W-90*3 API GL-5

CHASSIS — DIFFERENTIAL

FRONT DIFFERENTIAL A front differential that supports the independent front suspension has been adopted. The differential carrier has adopted a tube configuration to equalize the lengths of the right and left drive shafts. For the purpose of improving dust resistance, a type of oil seal with a side lip that contacts the dust cover has been adopted.

Tube Configuration

Oil Seal Dust Cover Side Lip

155CH13

REAR DIFFERENTIAL The tooth configuration of the gears has been optimized to reduce noise and vibration. Similar to the front differential, a type of oil seal with a side lip that contacts the dust cover has been adopted. Dust Cover Side Lip

155CH49

Oil Seal

155CH50

With LSD

155CH51

With Differential Lock Mechanism

CHASSIS — FRONT DRIVE SHAFT AND AXLES

FRONT DRIVE SHAFT DESCRIPTION In conjunction with the adoption of the independent front suspension, drive shafts which use the double offset type CVJ (Constant-Velocity Joint) on the differential side, and the Rzeppa type CVJ on the wheel side have been adopted.

Rzeppa Type CVJ

Double Offset Type CVJ

Wheel Side

Differential Side

155CH52

AXLES FRONT AXLE Tapered roller bearings are used on the front axle. Also, a needle bearing is used between the steering knuckle and the drive shaft. The hub bolt’s size, quantity, and PCD (Pitch Circle Diameter) have been changed. Specifications Model Item

Needle Bearing

Hub Bolt

Hub Bolt Size No. of the Hub Bolt P.C.D mm (in.)

New

M14 1.5

M12 1.5

150 (5.9)

139.7 (5.5)

Hub Nut Size* * : Width Across Flat

155CH53

Tapered Roller Bearings

CHASSIS — AXLES AND BRAKES

REAR AXLE The semi-floating axle is used for the rear axle. Unit type double-row angular ball bearing is used. The axle housing is provided with large reinforcements to realize excellent rigidity.

Unit Type Double-Row Angular Ball Bearing

Reinforcement

155CH55 155CH54

CHASSIS — BRAKES

BRAKES DESCRIPTION The brakes of the new model have following features. Four-piston opposed type calipers with reduced brake drag are used for the front brakes. The rear brake caliper has been changed to the FSX14 type caliper from the FS14 type caliper. The shape of the parking brake lever has been changed. A double-link type variable lever ratio brake pedal has been adopted. A hydraulic brake booster in which the ABS actuator and the P&B valve are integrated has been adopted.

CHASSIS — BRAKES

155CH16

Specifications Model Item Type Diameter Brake Booster Type Type Caliper Type Pad Area Front Brake Wheel Cylinder Dia. Master Cylinder

Rear Brake

New

mm (in.)

cm2 (in.2) mm (in.)

Rotor Size (D T)*1

mm (in.)

Type Caliper Type Pad Area Wheel Cylinder Dia.

cm2 (in.2) mm (in.)

Rotor Size (D T)*1

mm (in.)

Brake Control Valve Type Type Parking ki Size Brake Lever Type ABS *1: D: Outer Diameter, T: Thickness *2: Enclosed in Hydraulic Brake Booster

mm (in.)

Single (Double Piston) Tandem 26.99 (1.06) 25.4 (1.00) Hydraulic Vacuum Ventilated Disc S14 12 S13 13 58 (8.99) 50 (7.75) 48.1 2 42.85 2 45.4 2 45.4 2 (1.89 2 1.69 2) (1.79 2 1.79 2) 313 32 311 32 (12.32 1.26) (12.24 1.26) Ventilated Disc FSX14 FS14 36 (5.58) 37 (5.74) 48.1 (1.89) 329.4 18 335 18 (12.97 0.71) (13.19 0.71) P & B Valve*2 LSP & B Valve Drum 230 (9.06) Center Lever STD

CHASSIS — BRAKES

FRONT BRAKE The brake caliper with low brake drag is used on the new model. This caliper uses a stainless steel plate that is secured onto the piston. The plate has hooks that insert into the brake pad, and pad clips are used to secure the brake pad together with the rubber-coated shim onto the stainless steel plate. When the brake is released, and as the piston retracts, this construction allows the brake pad to separate from the disc rotor, thus reducing the brake drag. Furthermore, the size of the piston seal has been revised to increase the amount of piston retraction. Rubber-Coated Shim

Pad Clips Fixed

Brake Pad Brake Pad Pad Clips

Stainless Steel Plate

Piston

155CH56

Hooks

155CH11

Rubber-Coated Shim Stainless Steel Plate 155CH12

REAR BRAKE The FSX14 type brake caliper is used on the new model.

FSX14 Type Caliper

PARKING BRAKE

155CH57

The shape of the parking brake lever’s cable retractor has been changed to reduce the amount of the lever travel and to improve the operating feeling.

Cable Retractor 155CH58

CHASSIS — BRAKES

BRAKE PEDAL 1. General

Brake Pedal Lever

A duble-link type variable lever ratio brake pedal has been adopted to provide an excellent brake feeling.

2. Construction The link-type variable lever ratio brake pedal has adopted a construction in which the brake pedal and brake pedal lever are joined by a link to vary the lever ratio.

Link

Brake Pedal 155CH59

3. Operation Small Pedal Stroke When the pedal stroke is small, the lever ratio is set small, assuming a normal gradual brake application. Thus, the brake fluid is delivered quickly into the calipers to effect smooth braking. Medium Pedal Stroke When the pedal stroke is medium, the lever ratio is set large, assuming a full brake application such as sudden braking. Thus, the brake pedal effort is minimized. Large Pedal Stroke

Lever Ratio

When The pedal stroke is large, the lever ratio is set small in order to provide an appropriate amount of pedal rigidity. Thus, proper pedal response is realized.

Pedal Stroke 155CH60

CHASSIS — BRAKES

ABS 1. General The ABS actuator and the hydraulic brake booster have been integrated to form a compact actuator. The hydraulic brake booster uses the brake fluid that has been stored under high pressure to provide a power assist to the pedal effort that is applied to the brake pedal. Furthermore, the brake fluid that has been stored under high pressure is also used as the hydraulic pressure for controlling the ABS.

2. System Diagram

Hydraulic Brake Booster Combination Meter

Brake Fluid Level Warning Switch

Brake Warning Light ABS Warning Light

Switching Solenoid Valves

Hydraulic Brake Booster Warning Buzzer

Stop Light Switch

Control Solenoid Valves

Pump Motor

Pressure Switches (High and Low)

Solenoid Relay Pump Motor Relay Pump Motor Relay

Rear Diff. Lock Position Switch

ABS & Hydraulic Brake Booster ECU

L4 Position Switch Deceleration Sensor Center Diff. Lock Indicator Switch

Front Speed Sensor

Front Wheel

Rear Speed Sensor

Rear Wheel 155CH10

CHASSIS — BRAKES

3. Layout of Components ABS Warning Light Brake Warning Light Hydraulic Brake Booster Warning Buzzer Deceleration Sensor

Stop Light Switch

Rear Speed Sensor

Hydraulic Brake Booster Brake Fluid Level Warning Switch Pressure Switch

Rear Diff. Lock Position Switch L4 Position Switch Center Diff. Lock Indicator Switch ABS & Hydraulic Brake Booster ECU Solenoid Relay Pump Motor Relays

Front Speed Sensors

155CH45

4. Function of Components Components Speed Sensors Deceleration Sensor ABS & Hydraulic Brake Booster ECU Brake Fluid Level Warning Switch Hydraulic Brake Booster Pump Motor Relays Solenoid Relay ABS Warning Light Brake Warning Light Hydraulic Brake Booster Warning Buzzer Stop Light Switch Rear Diff. Lock Position Switch L4 Position Switch Center Diff. Lock Indicator Switch

Pressure Switches

Function Detect the wheel speed of each of four wheels. Detects the vehicle’s acceleration in the longitudinal direction. Controls the operation of the ABS brake and the hydraulic brake booster based on the signals received from the speed sensors, the deceleration sensor the pressure switches, etc. Detects the brake fluid level. Assists with the pedal effort applied to the brake pedal. Changes the fluid path based on the signals from the ABS & hydraulic brake booster ECU during the operation of the ABS, in order to control the fluid pressure that is applied to the wheel cylinders. Control the pump motor operation in the hydraulic brake booster. Supply power to the solenoid valves in the hydraulic brake booster. Lights up to alert the driver when the ECU detects the malfunction in the ABS. Lights up to alert the driver when the ECU detects the malfunction in the brake system. Emits a continuous sound to inform the driver that the ECU detects a malfunction in the hydraulic brake booster. Detects the brake signal. Detects the condition of the rear differential lock. Detects the transfer shifted in the low. Detects the condition of the center differential lock. Monitors the hydraulic pressure of the accumulator and outputs control signals for the pump motor. There are two types: the pressure switch PH for controlling the pump, and the pressure switch PL for giving a warning when the pressure is low.

CHASSIS — BRAKES

5. Construction and Operation of Main Components Deceleration Sensor A deceleration sensor that uses a semiconductor sensor is provided inside the center console. When a force is applied to the deceleration sensor, the semiconductor sensor flexes, and this distortion is measured and converted into an electric signal. This semiconductor sensor is used to detect the acceleration and deceleration rate in the vehicle’s longitudinal direction. Front

Semiconductor Sensor 155CH34

Hydraulic Brake Booster The hydraulic brake booster consists of the following components: Function

Components Pump and Pump Motor Accumulator

Pressure Switches

Relief Valve

Draws up the brake fluid from the reservoir tank and provides high hydraulic pressure to the accumulator. Stores the hydraulic pressure that was generated by the pump. The accumulator is filled with high-pressure nitrogen gas. Monitors the hydraulic pressure of the accumulator and outputs control signals for the pump motor. There are two types: the pressure switch PH for controlling the pump, and the pressure switch PL for giving a warning when the pressure is low. Returns the brake fluid to the reservoir tank to prevent excessive pressure if the pump operates continuously due to a malfunction of the pressure switch.

Reservoir Tank

Stores the brake fluid.

Brake Fluid Level Warning Switch

Detects the low brake fluid level.

Master Cylinder Brake Booster

P & B Valve Switching Solenoid Valves (SA1, SA2) Control Solenoid Valves Pressure Holding Valves Pressure Reduction Valves

Generates the hydraulic pressure that is provided to the wheel cylinders during normal braking. Regulates the accumulator pressure in accordance with the pedal effort that is applied to the brake pedal and introduces this pressure to the booster chamber in order to provide a power assist to the brakes. Controls the hydraulic pressure of the rear brake system to achieve an appropriate distribution of front/rear braking force. However, if the front brake system fails, the P&B valve does not control the hydraulic pressure of the rear brake system. Switches the brake hydraulic path when the ABS is activated, or normal braking is applied. Controls the hydraulic pressure that is applied to the wheel cylinders during ABS control.

CHASSIS — BRAKES

Hydraulic Circuit

High Pressure Nitrogen Gas Brake Fluid Level Warning Switch Reservoir Tank

Check Valve Accumulator Pump & Pump Motor Pressure Switch PH (High Pressure)

Relief Valve

Pressure Switch PL (Low Pressure)

Master Cylinder & Brake Booster

SA1

Switching Solenoid Valves SA2

P & B Valve Pressure Holding Valves Control Solenoid Valves

Rear Brakes

Front Brakes

Pressure Reduction Valves

155CH61

CHASSIS — BRAKES

1) Pump, Pump Motor, Accumulator, Pressure Switches and Relief Valve If the accumulator pressure becomes lower than the pressure that is specified in the pressure switch PH, which is used for detecting high pressure, the pressure switch PH turns OFF. Then, the ABS & hydraulic brake booster ECU turns ON the pump motor relays to operate the pump motor and the pump. The brake fluid that is discharged by the pump passes through the check valve and is stored in the accumulator. The hydraulic pressure that is stored in the accumulator is used for providing the hydraulic pressure that is needed for normal braking and for operating the ABS. If the accumulator pressure becomes higher than the pressure that is specified in the pressure switch PH, the pressure switch PH turns ON. Then, after several seconds, the ABS & hydraulic brake booster ECU turns OFF the pump. At this time, if the pressure switch PH malfunctions and causes the pump to operate continuously, the relief valve opens to prevent excessive pressure from being generated. Moreover, if the accumulator pressure becomes lower than the pressure that is specified in the pressure switch PL, which is used for detecting low pressure, the pressure switch PL turns OFF. As a result, the brake warning light turns ON and the brake warning buzzer activates. At this time, the ABS is prohibited from operating.

Reservoir Tank

Accumulator Pressure

Check Valve

Accumulator

Relief To Master Valve Cylinder and Solenoid Pressure Valves Switch PL

Pressure Switch PH Pressure Switch PL

ON OFF ON OFF

Time Pressure Switch PH

ABS & Hydraulic Brake Booster ECU

Pump and Pump Motor

Pump Motor

Relief Valve

Oprn Close

OFF

Pump Motor Relays

Brake Warning Light

Brake Waning Light ON and Brake OFF Warning Buzzer

Brake Warning Buzzer 152CH16

152CH17

CHASSIS — BRAKES

2) Master Cylinder and Brake Booster a. Construction This construction enables the hydraulic pressure that is generated by the brake booster to be applied directly to the rear brakes. The master cylinder is the center port type single master cylinder, which is used for the front brakes only. The brake booster is integrated with the master cylinder. The operating portion, master cylinder, and regulator are positioned coaxially to achieve a simple and compact construction. The master cylinder and brake booster consists of an operating rod, a power piston, master cylinder pistons, a regulator piston, a spool valve, a reaction rod and a rubber reaction disc. The operating rod and the power piston are linked directly to transmit the pedal effort that is applied to the brake pedal. The regulator piston and the spool valve are linked directly. A forward (leftward) force generated by the master cylinder pressure and a rearward (rightward) force generated by the power assist of the booster are applied to the regulator piston. Both forces maintain a balance. The regulator piston’s return spring is provided for the regulator piston to ensure the return of the spool valve. The master cylinder pistons have adopted a dual construction consisting of outer and inner pistons. Ordinarily, the outer and inner pistons operate in unison. If the accumulator pressure is not applied, only the inner piston operates to ensure braking force.

Reaction Rod

Rubber Reaction Disc

Master Cylinder Outer Piston Master Cylinder Inner Piston Return Spring Power Piston

Regulator Piston

Spool Valve

Return Spring

                                     

Operating Rod

Regulator

Master Cylinder

Operating Portion 155CH62

CHASSIS — BRAKES

86 b. Operation

i) Pressure Increase (Low Pressure) The pedal effort that is applied to the brake pedal is transmitted via the operating rod, power piston, and master cylinder inner piston. However, because the load setting of the master cylinder’s return spring is higher than that of the regulator piston’s return spring, the regulator piston gets pushed before the volume in the master cylinder becomes compressed. As a result, the spool valve moves forward. The spool valve closes the path A between the reservoir and the booster chamber (behind the power piston) and opens the path B between the accumulator and the booster chamber. Then, the pressurized brake fluid is introduced into the booster chamber to provide a power assist to the pedal effort. When the pressure is introduced into the booster chamber, the power assist overcomes the force of the master cylinder’s return spring. This causes the volume in the master cylinder to become compressed and increases the pressure that is applied to the front brakes. At the same time, the pressure in the booster chamber increases the pressure that is applied to the rear brakes. During the initial stage of the brake operation, the booster pressure that is applied to the rubber reaction disc is small. Therefore, a return force in the rightward direction does not apply to the spool valve via the reaction rod. Power Piston From To Regulator Piston From Reaction Rod Reservoir Accumulator

Reservoir

Spool Valve Operating Rod

Rubber Reaction Disc

Return Spring

Return Spring To Rear To Front Master Cylinder Brake Brake Inner Piston

Booster Chamber Master Cylinder Outer Piston 155CH05

ii) Pressure Increase (High Pressure) In contrast to the time when the pressure is low, when the pressure is high, the booster pressure that is applied to the rubber reaction disc increases. Accordingly, the rubber reaction disc deforms and causes a return force in the rightward direction to be applied to the spool valve via the reaction rod. Therefore, in contrast to the time when the pressure is low, a greater reaction force is transmitted to the brake pedal. As a result, a variable servo mechanism is realized, in which the servo ratio is lower during high pressure than during low pressure. From To From Power Piston Reaction Rod Reservoir Accumulator Reservoir Regulator Piston Rubber Reaction Disc

Master Cylinder Inner Piston

Spool Valve To Rear To Front Brake Brake

Booster Chamber Master Cylinder Outer Piston 155CH06

CHASSIS — BRAKES

iii) Holding This is a state in which the force that is applied via the brake pedal and the master cylinder pressure are in balance. The forces that are applied to the front and the rear of the regulator piston, in other words, forces that are generated by the master cylinder pressure and the regulator pressure become balanced. This causes the spool valve to close both path B from the booster chamber to the accumulator and path A to the reservoir. As a result, the brake system is in the holding state. Regulator Piston To From Reservoir Accumulator

A B

From Reservoir

Spool Valve To Rear Brake

To Front Brake

155CH07

iv) Pressure Reduce When the pressure that is applied to the brake pedal is relaxed, the master cylinder pressure decreases. Then, the regulator piston’s return (rightward) force becomes relatively greater, causing the regulator piston to retract and the spool valve to also retract. As a result, the path A between the reservoir and the booster chamber opens. The booster pressure becomes reduced in this state, creating a balance that corresponds to the force that is newly applied via the brake pedal. This process is performed repetitively to reduce the booster pressure and the master cylinder pressure in accordance with the force that is applied via the brake pedal. Regulator Piston To From Reservoir Accumulator To Reservoir

Booster Chamber

From Rear From Front Brake Brake

Spool Valve

155CH08

CHASSIS — BRAKES

v) During Power Supply Malfunction If the accumulator pressure is affected due to some type of malfunction, no pressure will be supplied by the regulator. Then, a power assist cannot be provided to the force that is applied via the brake pedal and the pressure to the rear brakes cannot be increased. Because the power assist is not applied to the master cylinder outer piston, the master cylinder outer piston does not operate and remains in its initial position. The pressure to the front brakes will be increased by the master cylinder inner piston in accordance with the pedal effort applied to the brake pedal. From Reservoir

To Front Brake

155CH09

3) Solenoid Valves a. Switching Solenoid Valves Two switching solenoid valves (SA1 and SA2) are provided. The control signals from the ABS & hydraulic brake booster ECU open and close the switching solenoid valves to switch the brake fluid paths. The solenoid valves SA1 and SA2 switch during normal braking of the front brakes and during the activation of the ABS. During normal braking, the path to the master cylinder side is opened, and the path to the booster chamber side is opened during the activation of the ABS. b. Control Solenoid Valves The control solenoid valve consists of 3 pressure holding valves and 3 pressure reduction valves. Each of the brake circuits consists of a pressure holding valve and a pressure reduction valve. The valves are turned ON and OFF during the activation of the ABS. The pressure increase mode, the pressure holding mode, and the pressure reduction mode are effected based on the combination of these valves that are turned ON and OFF, in order to control the hydraulic pressure that is applied to each of the wheel cylinders.

CHASSIS — BRAKES

c. System Operation i) Normal Braking During normal braking, all solenoid valves are turned OFF.

OF F

155CH17

Rear Brakes

Front Brakes

CHASSIS — BRAKES

90 ii) ABS Operation

The solenoid valves are turned ON and OFF as described below to switch the fluid paths in order to control the brakes. At this time, the hydraulic path between the master cylinder and the front brakes is shut off to prevent the brake pedal from vibrating and to improve the feeling during brake application.

Pressure Reduction Mode

Pressure Holding Mode

Pressure Increase Mode

O N

Rear Brakes

Front Brake

Rear R Brake

OF F 3

OF F

O N

Mode Solenoid Valves

O N

OF F

Front Brakes

155CH18

1 Solenoid Valve SA1, SA2

Pressure Reduction Mode ON

Pressure Holding Mode ON

Pressure Increase Mode ON

2 Pressure Holding Valve

OFF

3 Pressure Reduction Valve

OFF

Wheel Cylinder Pressure

Reduction

Hold

Increase

2 Pressure Holding Valve

OFF

3 Pressure Reduction Valve

OFF

Wheel Cylinder Pressure

Reduction

Hold

Increase

CHASSIS — SUSPENSION

SUSPENSION DESCRIPTION A lower torsion bar spring type double-wishbone independent suspension has been newly adopted for the front suspension. The rear suspension uses a 4-link coil spring with lateral rod type suspension as in the previous model. Excellent offroad drivability has been realized by achieving a longer suspension stroke. An active height control suspension and an adaptive variable suspension have been newly adopted.

155CH63

Specifications Model Item Tread

Front Wheel Alignment*

Front Rear Caster Camber Toe-In King Pin Inclination

*: Unloaded Vehicle Condition

mm (in.) mm (in.) degrees degrees mm (in.) degrees

New

1620 (63.8) 1615 (63.6) 3°05′ 0°00′ 0 12°15′

1595 (62.8) 1600 (63.0) 3°00′ 1°00′ 2 (0.08) 13°00′

CHASSIS — SUSPENSION

FRONT SUSPENSION 1. General A lower torsion bar type double-wishbone independent suspension is used. The vehicle’s offroad drivability is maintained by optimizing the allocation of the various components, resulting in excellent riding comfort, stability, and controllability. Upper Arm

Stabilizer

Lower Arm Torsion Bar Spring Shock Absorber 155CH64

2. Geometry The allocation of the upper and lower arms has been optimized to lower the roll center height during cornering. Accordingly, a stable postural behavior has been ensured during cornering and excellent cornering performance has been realized. In addition, the front suspension has adopted an anti-dive geometry to suppress the front dive during braking.

3. Steering Knuckle A steering knuckle that positions the upper arm higher has been adopted to maintain offroad drivability while providing excellent riding comfort, stability, and controllability. Through the adoption of this steering knuckle, the A-B distance between the kingpin offset and the axle center has been reduced. Accordingly, the rotational torque that is generated at the kingpin axis has been reduced, thus ensuring the vehicle’s stability during braking. In addition, the generation of flutter has been restrained.

Kingpin Axis

Tire Contact Center

Upper Arm

Steering Knuckle

B Axle Center

Lower Arm

Kingpin Offset

155CH65

CHASSIS — SUSPENSION During cornering, the force from the tire is applied to the arms as illustrated. This force, which is applied to the arms, influences the distance between the upper and lower arms, and has a tendency to decrease with the increase in the distance between the arms. Through the adoption of the steering knuckle that positions the upper arm higher, the force that is applied to the arms has been reduced. In addition, it enabled the suspension system to sufficiently withstand the lateral force even though a softer suspension arm bushing has been adopted. This resulted in excellent riding comfort, stability, and controllability.

Upper Arm The force applied to the upper arm The distance from the lower ball joint to the upper ball joint

Lower Arm

The force applied to the lower arm The lateral force applied to the tire

4. Upper Arm By mounting the upper arm higher, the force that is applied from the road has been reduced. Furthermore, by adopting the type of ball joint that is pressed into the arm, the offset between the ball joint center and the upper arm center has been minimized, thus reducing the torsional force that is applied to the upper arm. Accordingly, the construction of the upper arm has been simplified to that of a pressed single-sheet product.

155CH40

A’

A 155CH66 155CH37

A – A’ Cross Section

155CH38

5. Lower Arm To ensure a long suspension stroke, a long lower arm has been adopted. Also, to prevent road interference, the lower arm has been mounted higher. The lower arm has adopted a closed cross section to minimize damage in case of road interference. As in the upper arm, the lower arm has adopted the type of ball joint that is pressed into the arm, thus minimizing the offset between the ball joint center and the lower arm center and reducing the torsional force that is applied to the lower arm.

A’

A A – A’ Cross Section

155CH67 155CH35

155CH36

CHASSIS — SUSPENSION

6. Torsion Bar Spring To obtain a longer suspension stroke a lower torsion bar spring has been adopted. To prevent road interference, the torsion bar spring has been positioned higher than the under cover and the bottom of the frame. An anchor arm bracket, which is provided with an anchor arm, has been float-mounted to the anchor member via a rubber bushing. Accordingly, a longitudinal compliance of the front suspension has been ensured to provide excellent riding comfort. Front Torsion Bar Spring

Frame

Under Cover

155CH44

Anchor Member Torsion Bar Spring

Anchor Arm Bracket

Anchor Member

155CH68

Anchor Arm

Rubber Bushing View A

7. Stabilizer A solid bar type stabilizer is used to provide excellent riding comfort, stability and controllability.

CHASSIS — SUSPENSION

REAR SUSPENSION As in the previous model, a 4-link coil spring with lateral rod type suspension is used. However, the vehicle’s offroad drivability is maintained while providing excellent riding comfort, stability, and controllability by increasing the suspension stroke, increasing the tread, optimizing the bushing shape and characteristics, and optimizing the position of the control arms.

Lateral Rod Upper Control Arm Coil Spring

Shock Absorber Lower Control Arm

Stabilizer

155CH69

CHASSIS — SUSPENSION

ACTIVE HEIGHT CONTROL SUSPENSION AND ADAPTIVE VARIABLE SUSPENSION 1. General The active height control suspension and adaptive variable suspension is a suspension system in which comfort and convenience have been significantly improved through the integration of a vehicle height adjustment system and a damping force control system. The vehicle height adjustment system improves the occupants’ in-and-out access by quickly lowering the vehicle height at the touch of a switch. Furthermore, by raising the vehicle height, the occurrence of road interference can be minimized on unpaved roads. Also, by maintaining a constant vehicle height regardless of the load conditions such as the number of occupants or the weight of the cargo, under the prescribed loading condition the suspension stroke can be utilized effectively to ensure constantly stable riding comfort. Based on the skyhook theory, the damping force control system controls the suspension to achieve an optimal damping force in accordance with the bumpiness of the road surface. Furthermore, through the use of the various types of sensors, this system detects the vehicle’s operating condition to obtain an optimal damping force to provide excellent riding comfort, stability, and controllability.

2. System Function Vehicle Height Control Function 1) Vehicle Height Selection Function The following three types of vehicle heights can be selected by operating the switch: normal vehicle height (N), low vehicle height (Lo), and high vehicle height (Hi). Selected Height Position Front Vehicle Height Rear

Vehicle Height Adjustment Speed

Up Down

Lo Approximately –50 mm (–2.0 in.) Approximately –40 mm (–1.6 in.)

N Hi Standard Approximately Vehicle Height +40 mm (+1.6 in.) Standard Approximately Vehicle Height +50 mm (+2.0 in.) Lo to N or N to Hi Approximately 10 to 15 seconds (Main accumulator in the stored state) Hi to N or N to Lo Approximately 3 to 8 seconds

2) Automatic Leveling Function This function maintains the vehicle height constant regardless of the load conditions such as the number of occupants or the weight of the cargo under the prescribed loading condition. It effects constant control so that the vehicle height is maintained at a prescribed value when the normal vehicle height is selected.

CHASSIS — SUSPENSION

3) Vehicle Speed Sensing Function This function automatically adjusts the vehicle height in accordance with the vehicle speed in order to ensure stability and riding comfort while driving. During Hi Position

During Lo Position HI

During Hi Position* HI 25mm

5 km/h (3 mph)

Vehicle Speed

30 km/h Vehicle (19 mph) Speed

155CH19

155CH20

When the vehicle speed becomes higher than approximately 5 km/h (3 mph), the vehicle height transfers to normal. The normal vehicle height is maintained even if the vehicle speed becomes lower than 5 km/h (3 mph).

When the vehicle speed becomes higher than approximately 30 km/h (19 mph), the vehicle height transfers to normal. The normal vehicle height is maintained even if the vehicle speed becomes lower than 30 km/h (19 mph).

20 km/h 50 km/h Vehicle (12.5 mph) (31 mph) Speed 155CH21

When the vehicle speed becomes higher than approximately 50 km/h (31 mph), the vehicle height transfers to a height that is approximately 25 mm (1 in.) higher than the normal vehicle height. When the vehicle speed becomes lower than approximately 20 km/h (12.5 mph), it returns to the high vehicle height.

*: Transfer shifted in the low. 4) Extra High Mode While driving on an unpaved road with the transfer shifted in the low range and the vehicle height set to high, if one of the wheels freewheels, the vehicle height raises automatically by approximately 30 mm (1.2 in.) at the front and approximately 20 mm (0.8 in.) at the rear. 5) Vehicle Height Adjustment Prohibition Control When the vehicle is raised on a jack or is being towed, the vehicle adjustment can be prohibited by operating the height control switch. However, the prohibition control cancels automatically when the vehicle speed becomes higher than approximately 80 km/h (50 mph) at the normal vehicle height, or higher than approximately 30 km/h (19 mph) at the high or low vehicle height.

NOTE:

Occasionally, the set vehicle height may not be maintained when the vehicle is carrying a load that is heavier than a prescribed amount. At times, it might not be possible to raise the vehicle height even by operating the switch. Up to 4 occupants* plus about 300 kg (661 lb.) in the normal mode Up to 4 occupants* plus about 170 kg (375 lb.) in the high mode *: About 68 kg (150 lb.) for a person

CHASSIS — SUSPENSION

Damping Force Control Function 1) Float and Pitch Control (Skyhook Control) Based on the skyhook theory to take semi-active control of the damping force, this function effects independent front/rear control of the damping force in order to achieve an optimal damping force in accordance with the bumpiness of the road surface. The suspension control ECU calculates the relative speed between the body and the wheels based on the signals received from the height control sensor and controls the actuators to maintain a flat and stable vehicle posture in various road conditions. a. Skyhook Theory This theory proposes an imaginary shock absorber suspended in the air. This imaginary shock absorber is inactive against any force that is applied from the ground, but effectively activates a damping force against body vibrations.

Imaginary Shock Absorber

Body

Body Shock Absorber

Spring

Spring Skyhook Suspension

Conventional Suspension

155CH22

b. Semi-Active Control The conditions in which the vehicle overcomes mild bumps are demonstrated through the use of a model in the following four conditions: 1 The shock absorber contracts and the body moves upward. 2 The body keeps moving upward causing the shock absorber to elongate gradually. 3 The shock absorber keeps elongating and the body starts moving downward. 4 The body keeps moving downward causing the shock absorber to contract gradually. Stage 2

Stage 1

Stage 3

Body Movement Damping Force

Easy to Contract

155CH23

Assisting the Vibrations

Stage 4 Damping Force Body Movement

Hard to Expand

Body Movement Damping Force Easy to Expand

Hard to Contract

155CH24

155CH25

155CH26

Suppressing the Vibrations

Assisting the Vibrations

Suppressing the Vibrations

Thus, during stages 1 and 3 the shock absorbers assist the vibration to create a softer damping force, and during stages 2 and 4 the shock absorber suppress the vibration to create a hard damping force, the shock absorbers are minutely controlled to suppress the vibration to restrain the movement of the body and of the shock absorbers. The above processes are performed independently between the front and rear wheels in order to stabilize the vehicle to a flat posture.

CHASSIS — SUSPENSION

2) Thumping Sensitive Control When the road surface condition does not require a damping force, this function controls the actuator so that their damping force will not increase. As a result, both flatness and a soft ride have been achieved. 3) Unsprung Vibration Control If unsprung resonance is detected, this function controls so that the damping force will not decrease below a certain level, in order to reduce the unsprung resonance. As a result, excellent road-holding performance has been ensured without affecting riding comfort. 4) Speed Sensitive Control To optimally balance the vehicle’s riding comfort and road-holding performance, the damping force is increased along with the increase in vehicle speed, in order to ensure stability during high-speed driving. 5) Anti-Roll Control During cornering, this function makes the damping force firmer, thus restrating the body roll speed in order to provide excellent stability and controllability. 6) Anti-Dive Control During braking, this function makes the damping force firmer to restrain the body dive, thus ensuring excellent stability and controllability. 7) Anti-Squat Control During acceleration, this function makes the damping force firmer to minimize the changes in the vehicle body posture to provide excellent stability and controllability. 8) Damping Force Control The actuator uses a 16-step step motor to generate a continually variable damping force. This provides a wide selection of damping force and enables a smooth transition of the damping force. As a result, a minutely controlled damping force that accommodates various types of driving conditions has been made possible. Right-Left Wheel Communicating Function Normally, an oil passage remains open between the shock absorbers for the right and left wheels. This enables the suspension to contract and elongate smoothly when the right and left wheels move gradually at opposite phases and provides excellent road-holding performance while driving on a winding road. When the driver operates the steering wheel, the oil passage between the right and left shock absorbers closes according to that condition. This restrains the increase of the vehicle body roll during cornering, thus ensuring the vehicle’s stability and controllability.

CHASSIS — SUSPENSION

100

3. Layout of Components Gas Chambers & Damping Force Control Actuators Pump & Motor

Rear Height Control Senser

Pump Attenuator Shock Absorber

Front Height Control Sensors

Shock Absorber

Height Control Accumulator Front Speed Sensor

Control Valve Assembly 155CH94

Height Control Indicator Light Height Control OFF Indicator Light

Steering Angle Sensor

Suspension Control ECU

Stop Light Switch Height Select Switch Height Control Switch Damping Mode Select Switch 155CH95

CHASSIS — SUSPENSION

101

4. Function of Components Components Height Control Indicator Light

Height Control OFF Indicator Light

Height Select Switch Height Control Switch Damping Mode Select Switch Front Speed Sensors Height Control Sensors Steering Angle Sensor Pump and Motor Reservoir Tank Return Valve Pressure Sensor Temperature Sensor Pump Attenuator Height Control Accumulator Control Valve Assembly

Leveling Valves Gate Valves

Gas Chambers Damping Force Control Actuators Shock Absorbers High Pressure Hose Suspension Control ECU Center Diff. Lock Indicator Switch L4 Position Switch Stop Light Switch Courtesy Switches Generator L Terminal AHC Main Relay AHC Motor Relay

Function Indicates the present vehicle height condition. • Lights to inform the driver when the active height control system is turned OFF by the height control OFF switch. • Blinks to alert the driver when the ECU detects the malfunction in the active height control suspension and adaptive variable suspension. • Indicates the diagnostic code. Selects the target vehicle height. Prohibits the adjustment of the vehicle height. Selects a damping force control mode. Detect the wheel speed. Detect the vehicle height. Detects the steering direction and angle of the steering wheel. Generates the high hydraulic pressure that is necessary for raising the vehicle height. Maintains the amount of fluid that is returned during the low vehicle height and the amount of fluid that is discharged during the high vehicle height. Opens and closes the oil passage between the control valve assembly and the reservoir tank. Detects the pump’s discharge pressure. Detects the fluid temperature. Dampens the hydraulic pulsation of the fluid that is discharged by the pump. Stores the hydraulic pressure to accelerate the speed in which the vehicle height is raised. Opens and closes the oil passage between the pump and the gas chambers of the wheels. Opens and closes the oil passage between the right and left shock absorbers. Performs the same functions as those of the gas chamber of the conventional shock absorber. Switches the damping force. Generates a damping force similar to the conventional shock absorber. Serves as the oil passage that links the gas chamber and the shock absorbers. Controls the entire system by performing the calculations for height control and damping force control based on the signals received from the sensors and switches. Detects that the center differential is locked. Detects the transfer shifted in the low. Detects the brake signal. Detects the open and closed condition of the doors. Detects that the engine is operating. Supplies power to the suspension system. Supplies power to the pump motor.

CHASSIS — SUSPENSION

102

5. Construction and Operation of Main Components Indicator Lights 1) Height Control Indicator Light The height control indicator light has been provided below the tachometer in the combination meter. It informs the driver by illuminating the indicator light for the present vehicle height position. When the height select switch is pressed to effect height control, the indicator for the present height position turns OFF and the indicator light for the target height position blinks. After height control is completed, the indicator light for the height position that has been attained illuminates.

Height Control Indicator

Height Control OFF Indicator 155CH70

2) Height Control OFF Indicator Light The height control OFF indicator light is located under the height control indicator light. This indicator light lights up to inform the driver when the active height control system is turned off by the height control switch. This indicator light blinks to alert the driver when the ECU detects the malfunction in the active height control and electric modulated suspension. By effecting the DTC (Diagnostic Trouble Code) check mode, the DTCs can be obtained from this indicator light. For details, see the 1998 LX470 Repair Manual (Pub. No. RM620U). Control Switches The height select switch, the height control switch and the damping mode select switch are located in front of the shift lever. Damping Mode Select Switch

Height Control Switch 155CH43

Height Select Switch

CHASSIS — SUSPENSION

103

1) Height Select Switch A seesaw type momentary switch has been adopted for the height select switch that is used for selecting a desired height. Pressing the (up) side of the switch once raises the vehicle height, and pressing the (down) side once lowers the vehicle height. 2) Height Control Switch Pressing this switch prohibits the height control function. Pressing it again cancels the prohibition. The prohibition cancels automatically when the vehicle speed becomes higher than 80 km/h (50 mph) at the normal vehicle height, or higher than 30 km/h (19 mph) at any other vehicle height. The state of height control prohibition is stored in memory even after the ignition switch has been turned OFF. 3) Damping Mode Select Switch As shown on the right, this control switch enables the driver to select a desired damping force from the 4 modes.

HARD

Damping Force

SOFT COMFORT

155CH27

SPORT

Select Switch Position Front Speed Sensors The sensors detect the individual speeds of the front wheels. The wheel speed signals are then input into the suspension control ECU via the ABS & hydraulic brake booster ECU. Height Control Sensors A total of 3 sliding resistance type height control sensors are provided: 1 in each of the right and left front wheel housings and 1 in the center of the cross member located above the rear axle. The sensor consists of a brush that is integrated with a shaft, which slides on the resistor that is formed on a substrate. Because the resistance value between the brush and the resistor terminal varies in proportion to the shaft’s rotational angle, a prescribed amount of voltage is applied to the resistor so that a change in the rotational angle can be detected in the form of a voltage change. Brush Resistor Brush

Rotational Angle

Output Voltage Input Voltage 155CH71

Cross Section

155CH41

Diagram of the Principle

CHASSIS — SUSPENSION

104 Steering Angle Sensor

The steering angle sensor is fitted to the turn signal switch assembly and detects the steering direction and angle. The sensor contains 2 photo interrupters with phases, and a slotted disc interrupts the light to turn the photo transistor ON and OFF to detect the steering direction and angle.

Steering Angle Sensor

Turn Signal Switch Assembly

Slotted Disc 155CH42

Pump and Motor A system in which the pump, pump motor, reservoir tank, return valve, pressure sensor, and temperature sensor are integrated has been adopted. Pump Motor

Pump

Return Valve

A’

A – A’ Cross Section

155CH72

Pressure Sensor

B’

155CH73

B – B’ Cross Section 155CH28

Temperature Sensor

1) Pump An external gear pump that contains less parts and excels in durability has been adopted. Also, the pump is a pressure-loading type in which the discharge pressure of the pump itself is utilized and routed via the gear case to push on the side of the pump gear in order to reduce the internal leakage, thus making high-pressure discharge possible.

High Pressure

Gear Case Pump Gear

Gear Case Pump Gear Discharge

155CH74

155CH75

CHASSIS — SUSPENSION

105

2) Motor A DC motor with 4-pole brushes has been adopted to realize excellent durability and high torque. 3) Return Valve The return valve opens and closes the oil passage between the control valve assembly and the reservoir tank. The return valve has been simplified by adopting a construction in which the valve is closed by the flow of the discharged fluid. Normally, a spring force is applied to the return valve to maintain the oil passage between the control valve assembly and the reservoir tank open. When the pump operates in order to raise the vehicle height, the pressure of the fluid that is discharged by the pump causes the return valve to move to the left of the diagram as illustrated. Accordingly, the oil passage between the control valve assembly and the reservoir tank closes, and the fluid that is discharged from the pump flows towards the control valve assembly. To Control Valve Assembly From Pump

From Control Valve Assembly Return Valve “Open”

Return Valve “Close”

155CH76

To Reservoir Tank Pump in Operation

Normal Condition Pump Attenuator The pump attenuator dampens the hydraulic pulsation of the fluid that is discharged by the pump. A bellows type accumulator that is made of stainless steel, which offers excellent gas penetration resistance and good pulsation absorption performance, has been adopted.

Specifications Sealed Gas Gas Chamber Volume cc (cu in.) Sealed Gas Pressure MPa (kgf/cm2, psi)

Bellows Oil Pressure

Nitrogen Gas Nitrogen Gas 2 (0.12) 1.96 (20, 284)

155CH77

CHASSIS — SUSPENSION

106 Height Control Accumulator

A free piston type accumulator, which provides a large gas chamber capacity, has been adopted for the height control accumulator. The height control accumulator consists of a cylinder, free piston, and solenoid valve. When raising the vehicle height, the accumulator discharges the stored fluid to accelerate the raising speed. Normally, the solenoid valve remains closed. When the vehicle height is being raised or the fluid is being stored in the main accumulator, the solenoid valve opens in accordance with the signal received from the suspension control ECU.

Specifications Sealed Gas Gas Chamber Volume cc (cu in.) Sealed Gas Pressure MPa (kgf/cm2, psi)

Nitrogen Gas 945 (57.7) 5.9 (60, 853)

Free Piston

Solenoid Valve Nitrogen Gas

155CH78

Control Valve Assembly The control valve assembly consists of the leveling valves for adjusting the vehicle height and the gate valves for controlling the right-left wheel communicating function. There are 4 valves each for the front and rear. Rear Gate Valve

Front Gate Valve

A’

Rear Leveling Valve

Front Leveling Valve

A – A’ Cross Section 155CH79

CHASSIS — SUSPENSION

107

1) Leveling Valve This valve opens and closes the oil passage between the pump and the gas chamber located at each wheel. Normally, the oil passage remains closed, and during vehicle height control, the oil passage opens in accordance with the signal received from the suspension control ECU.

Wheel Side

Pump Side

Wheel Side

Pump Side Open

155CH80

2) Gate Valve This valve opens and closes the oil passage between the right and left shock absorbers. Normally, the oil passage remains open, connecting the right and left shock absorbers. When the suspension control ECU determines that the oil passage between the right and left shock absorbers must be closed, the gate valve activates to close the oil passage.

Left Side

Right Side Open

Left Side

Right Side Close 155CH81

CHASSIS — SUSPENSION

108

Gas Chamber and Damping Force Control Actuator A gas chamber (a substitute for the gas chamber in the conventional shock absorber) and an actuator to switch the damping force have been integrated. The housing is provided with heat dissipating fins to improve the dissipation of the heat that is generated by the actuator.

Gas Chamber

Damping Force Control Actuator

155CH93

Heat Dissipating Fins 1) Gas Chamber The gas chamber uses the bladder type hydropneumatic accumlator. A resin membrane is sandwiched between rubber layers to realize excellent gas penetration resistance. The internal pressure of the gas chamber is varied by allowing the fluid to flow in and out of this gas chamber in order to raise or lower the vehicle height.

Nitrogen Gas

Specifications Sealed Gas Gas Chamber Volume cc (cu in.) Sealed Gas Pressure MPa (kgf/cm2, psi)

155CH82

Front Nitrogen Gas 400 (24.4) 2.26 (23, 327)

Rear 500 (30.5) 2.65 (27, 384)

2) Damping Force Control Actuator The pressure resistance performance of this actuator has been improved based on the actuator that has been adopted on the electric modulated suspension of the ES300. This actuator consists of the 16 steps step motor, a screw mechanism (which converts the rotational movement to a linear movement), a spool valve, a soft damping force valve and hard damping force valve. Signals from the suspension control ECU activate the actuator causing the spool valve to switch the oil passage. Thus, the volume of oil that passes through each valve is varied in order to control the damping force in 16 steps.

CHASSIS — SUSPENSION

109

Soft Damping Force Valve Hard Damping Force Valve

16 Steps Step Motor

Screw Mechanism

155CH83

Spool Valve : Flow of the Oil

Contraction Expansion Soft

Contraction Expansion Damping Force

Contraction Expansion Hard 155CH84

Shock Absorber The shock absorber has adopted a dual construction using a high-pressure main seal made of fluoroethylene resin and a high-pressure oil seal made of nitrile rubber and provided with a backup ring in order to ensure sealing performance and to reduce friction. High Pressure Oil Seal

High Pressure Main Seal

155CH29

Front Shock Absorber

155CH30

Rear Shock Absorber

155CH14

Seals

CHASSIS — SUSPENSION

110 Fluid

This system uses a fluid called the “Active Suspension Fluid AHC”. Suspension Control ECU 1) General The suspension control ECU is located in the driver’s side instrument panel. Based on the signals received from the sensors and switches, the suspension control ECU detects the vehicle height and vehicle conditions and outputs the control signals to the actuators and the pump. Front Right Height Control Sensor

Pump & Motor

Front Left Height Control Sensor

Front Right Damping Force Control Actuator

Rear Height Control Sensor

Front Left Damping Force Control Actuator

Steering Angle Sensor

Rear Right Damping Force Control Actuator

Pressure Sensor

Rear Left Damping Force Control Actuator

Temperature Sensor

Height Control Accumulator Solenoid Valve

ABS & Hydraulic Brake Booster ECU

Suspension Control ECU

Control Valve Assembly

Generator L Terminal

Front Leveling Valve

Center Diff. Lock Position Switch

Front Gate Valve

L4 Position Switch Stop Light Switch

Rear Leveling Valve Rear Gate Valve

Courtesy Switches

Height Control Indicator Light

Height Select Switch

Height Control OFF Indicator Light

Height Control Switch

DLC1

Damping Mode Select Switch

DLC3

CHASSIS — SUSPENSION

111

2) Self-Diagnosis If the suspension control ECU detects a malfunction in this system, it blinks the height control OFF indicator light to alert the driver of the malfunction. The ECU will also store the codes of the malfunctions. The diagnostic trouble codes (DTCs) can be accessed through the blinking of the height control OFF indicator light or the use of a Lexus hand-held tester. For details, see the 1998 LX470 Repair Manual (Pub. No. RM620U). 3) Test Mode The operation of the sensors and the switches can be inspected in the test mode. For details, see the 1998 LX470 Repair Manual (Pub. No. RM620U). 4) Active Test A Lexus hand-held tester can be used to activate the actuators for inspecting their operation. For details, see the 1998 LX470 Repair Manual (Pub. No. RM620U). 5) Fail-Safe If a malfunction occurs in any of the sensors or actuator, the ECU prohibits the vehicle height control and the damping force control.

CHASSIS — SUSPENSION

112

6. System Operation Normal Driving (Straightline Driving) The high pressure in the gas chamber and the shock absorber is shut off with the leveling valve. The gate valve remains open, and the right and left shock absorbers remain connected. The damping force is controlled in accordance with road surface conditions. Solenoid Valve Height Control Pressure Sensor Reservoir Tank

Retur n Val ve

Accumulator

Leveling Valve “Close”

Gas Chamber and Damping Force Control Actuator

Gate Valve “Open”

Pump and Motor Pump Attenuator

Leveling Valve “Close”

Gate Valve “Open”

Shock Absorbers 155CH85

Cornering The high pressure in the gas chamber and the shock absorber is shut off with the leveling valve. The gate vale is closed, and the right and left shock absorbers are shut off from each other. The damping force is controlled in accordance with road surface conditions and the operating condition of the steering wheel. Solenoid Valve Height Control Pressure Sensor Reservoir Tank

Retur n Val ve

Accumulator

Leveling Valve “Close”

Gas Chamber and Damping Force Control Actuator

Gate Valve “Close”

Pump and Motor Pump Attenuator

Leveling Valve “Close”

Gate Valve “Close”

Shock Absorbers 155CH85

CHASSIS — SUSPENSION

113

Raising the Vehicle Height Operating the height select switch to raise the vehicle height activates the pump motor, which rotates the pump. The fluid that is discharged by the pump is sent to the gas chambers and shock absorbers in order to raise the vehicle height. 1) Vehicle Stopped The solenoid valve of the height control accumulator is opened in order to use the fluid that is stored in the height control accumulator, which accelerates the raising speed of the vehicle height. To use the fluid that is stored in the accumulator, the front and rear leveling valves are opened simultaneously to raise all 4 wheels at the same time. When the stored fluid has been depleted, the front and rear leveling valves are opened alternately to raise the suspension of the front wheels and the rear wheels alternately. 2) Vehicle in Motion When the vehicle speed is less than approximately 25 km/h (16 mph), the fluid that is stored in the height control accumulator is used in the same way as when the vehicle is stopped. When the vehicle speed is higher than approximately 25 km/h (16 mph), the vehicle height is raised using only the fluid that is discharged by the pump, without using the height control accumulator. At this time, the front and rear leveling valves are opened alternately to raise the suspension of the front wheels and the rear wheels alternately. When the vehicle height it at low, it is automatically raised to normal when the vehicle speed becomes higher than approximately 5 km/h (3 mph). At this time, the fluid that is stored in the height control accumulator is also used. Solenoid Valve : Oil Flow Height Control Pressure Sensor Reservoir Tank

Return Valve

Accumulator

Leveling Valve

Gas Chamber and Damping Force Control Actuator

Gate Valve

Pump and Motor Pump Attenuator

Leveling Valve

Shock Absorbers

Gate Valve

155CH86

Vehicle Stopped Condition

Control Valve Assembly

Front Rear

Leveling Valve Gate Valve Leveling Valve Gate Valve

Height Control Accumulator Solenoid Valve Pump and Motor

Vehicle in Motion

Use Height Control Accumulator

Not Use Height Control Accumulator

25 km/h (16 mph) or less and at the time of using the height control accumulator

Open Open Open Open

Open and Close Open Open and Close Open

Open Open Open Open

Open and Close Open Open and Close Open

Open Operation

Close Operation

Open Operation

Close Operation

Except the left mentioned condition

CHASSIS — SUSPENSION

114

Fluid Stored in Height Control Accumulator Normally, the height control accumulator stores only the amount of fluid that is equivalent to that used in raising the vehicle height once. Therefore, after the vehicle has been raised from low to normal, or from normal to high, it is necessary to replenish the fluid in the height control accumulator. At this time, the pump motor is operated to rotate the pump, the leveling valves are closed, the solenoid valve of the height control accumulator is opened, and the fluid is stored in the height control accumulator. When the vehicle height is raised while the fluid that is stored in the height control accumulator has not reached a prescribed pressure, only the fluid that is discharged by the pump is used for raising the vehicle height, without using the fluid in the height control accumulator.

Solenoid Valve Pressure Sensor Reservoir Tank

Return Valve

: Oil Flow

Height Control Accumulator

Leveling Valve

Gas Chamber and Damping Force Control Actuator

Gate Valve

Pump and Motor Pump Attenuator

Leveling Valve

Shock Absorbers

Gate Valve

155CH87

Leveling Valve Gate Valve Leveling Valve Rear Gate Valve Height Control Accumulator Solenoid Valve Control Val e Valve Assembly

Front

Pump and Motor

Close Open Close Open Open Operation

CHASSIS — SUSPENSION

115

Lowering the Vehicle Height 1) Vehicle Speed Under 5 km/h (3 mph) When the height select switch is operated to lower the vehicle height from high to normal, or from normal to low, the front and rear leveling valves are opened simultaneously to allow the fluid in the gas chambers and the shock absorbers at the 4 wheels to return to the reservoir tank, causing the height of the suspension at all 4 wheels to become lowered at the same time. However, if the rear side is expected to become lower more quickly due to the load condition, and the difference between the lowering of the front side and the rear side becomes greater than a prescribed value, the rear leveling valve closes once, allowing only the vehicle height to become lowered at the front side. This feature prevents the headlights from being aimed upward. 2) Vehicle Speed Over 5 km/h (3 mph) When the height select switch is operated to lower the vehicle height from high to normal, the front and rear leveling valves are opened alternately to lower the suspension of the front wheels and the rear wheels alternately. When the vehicle speed is higher than approximately 5 km/h (3 mph), the vehicle height will not be lowered from normal to low.

Solenoid Valve Pressure Sensor Reservoir Tank

Return Valve

: Oil Flow

Height Control Accumulator

Leveling Valve

Gas Chamber and Damping Force Control Actuator

Gate Valve

Pump and Motor Pump Attenuator

Leveling Valve

Shock Absorbers

Gate Valve

155CH88

Condition Leveling Valve Control Gate Valve Val e Valve Leveling Valve Assembly Rear Gate Valve Height Control Accumulator Solenoid Valve Pump and Motor Front

Under 5 km/h (3 mph) When lowering Except lowering the four wheels the four wheels simultaneously simultaneously

Over 5 km/h (3 mph)

Open Open Open Open

Open or Close Open Open or Close Open

Open and Close Open Open and Close Open

Stop

CHASSIS — STEERING

116

STEERING DESCRIPTION The engine revolution sensing type rack and pinion power steering is used. A power tilt and power telescopic mechanism with memory function is used. An energy absorbing plate type energy absorbing mechanism is used in the steering column.

Reservoir Tank

Steering Column

Power Steering Pump

Steering Gear Box

155CH31

Specifications Gear Ratio (Overall) No. of Turns Lock to Lock Rack Stroke Fluid Type

19.8 3.8 mm (in.)

178 (7.01) ATF Type DEXRON II or III

CHASSIS — STEERING

117

STEERING GEAR A compact and lightweight rack and pinion type steering gear has been adopted to provide a good steering feeling. A cold-forged pinion gear with an improved precision of the gear tooth flank has been adopted to improve the steering feeling. The hydraulic characteristics have been optimized to enable the steering to be handled easily during stationary and low-speed conditions and to provide substantial response in the medium- to high-speed range. A roller type rack guide is used to realize smoother steering feeling and excellent steering response. A

155CH89

A’

Roller Type Rack Guide

Cold-Forging Pinion Gear 155CH92

A – A’ Cross Section

CHASSIS — STEERING

118

POWER TILT AND POWER TELESCOPIC STEERING COLUMN 1. General A compact and lightweight power tilt and power telescopic steering column that uses ultrasonic motors has been adopted. The auto set function has been adopted. The steering column can be set to 2 positions in conjunction with the driving position memory function. A self-diagnosis function is used.

2. System Diagram Tilt and Telescopic Manual Switch

Mirror ECU Tilt Motor and Tilt Position Sensor

Tilt & Telescopic ECU

Unlock Warning Switch (Ignition Switch)

Instrument Panel ECU

Telescopic Motor and Telescopic Position Sensor

DLC3 Seat ECU

Driving Position Memory Switch

155CH15

3. Construction Using ultrasonic motors that feature low-speed and high-torque characteristics, the power tilt and power telescopic steering column has adopted a compact and light weight tilt and telescopic mechanism that does not require a reduction mechanism. Each of the ultrasonic motors contains a position sensor that uses a Hall IC and a magnet to detect the tilt position or the telescopic position. The tilt and telescopic mechanism uses a screw mechanism to convert the motor’s rotational movement to a linear movement.

Telescopic Motor

Tilt Motor Screw Mechanisms 155CH90

CHASSIS — STEERING

119

4. Operation Manual Operation The tilt position and the telescopic position can be adjusted as desired by operating the tilt and telescopic switch. A stepless adjustment enables the tilt mechanism to be tilted 12 vertically, and the telescopic mechanism to be moved 42mm (1.65 in.) longitudinally.

12°

42 mm (1.65 in.) Tilt

Telescopic 155CH91

Auto Set Function When the ignition key is removed, the steering column moves forward away from the driver and also tilts up for easy exit and entry. When the ignition key is inserted in the ignition switch, the steering column returns to the previously set position. The auto set function can be prohibited by using a Lexus hand-held tester. Position Detection The rotation of the motor is sensed and the tilt and telescopic positions are detected by the position sensor in the motor, which uses a Hall IC and a magnet. Driving Position Memory Function Pressing the driving position memory switch that is located in the driver’s door duplicates the tilt and telescopic positions that have been previously stored in memory. Up to 2 sets of tilt and telescopic position can be stored. Self-Diagnosis Function If the tilt and telescopic ECU detects a malfunction in the power tilt and power telescopic system, the ECU stores the malfunction data in memory. Then, by connecting a Lexus hand-held tester to the DLC3 terminal, the diagnostic trouble codes (DTCs) can be accessed and an active test can be performed. For details, see the 1998 LX470 Repair Manual (Pub. No. RM620U).

CHASSIS — STEERING

120

ENERGY ABSORBING MECHANISM 1. Construction The energy absorbing mechanism in the steering column consists of a lower bracket, breakaway bracket, energy absorbing plate and a contractile main shaft. The steering column is mounted onto the instrument panel reinforcement via a lower bracket and breakaway bracket which is supported via a capsule and energy absorbing plate. The steering column and the steering gear box are connected with an intermediate shaft that contains a corrugated tube. In addition, the stoppers are provided on the lower bracket and the dash panel to regulate the amount of stroke against the impact applied from the gear box. Energy Absorbing Plate

Lower Bracket Dash Panel Main Shaft

Breakaway Bracket

Steering Gear Box Stoppers Intermediate Shaft 155CH32

2. Operation When the steering gear box moves during a collision (primary collision), the corrugated tube of intermediate shaft deformes and, the main shaft contracts, thus reducing the steering column and the steering wheel from protruding into the cabin. When an impact is transmitted to the steering wheel in a collision (secondary collision), the steering wheel and the steering wheel pad help absorb the impact. In addition, the breakaway bracket and the lower bracket separate, causing the entire steering column to move forward. As this time, the energy absorbing plate becomes deformed to help absorb the impact of the secondary collision. Deform (Energy Absorbing Plate) Secondary Collision Separate

Separate Contract Primary Collision

Deform 155CH33

BODY — HIGHLY RIGID BODY

121

BODY HIGHLY RIGID BODY The body of the LX470 has been made lightweight and highly rigid through the refinement of the shape and construction of each part, optimized allocation of reinforcements and members, and use of high strength sheet steel.

HIGH STRENGTH SHEET STEEL High strength sheet steel is used for the hood and door panels, etc. : High Strength Sheet Steel

155BO53

BODY — HIGHLY RIGID BODY

122

BODY SHELL The areas that join the pillars to the roof side rail or the rocker are provided with reinforcements to ensure a strong pillar construction. In addition, reinforcements are efficiently located throughout the body to realize excellent body rigidity. : Reinforcements

155BO29

The side member panel has been integrated in order to realize excellent panel precision and joining rigidity.

New

155BO02

155BO03

BODY — HIGHLY RIGID BODY

123

DOORS Pipe type side impact protection beams are mounted in the center space between the outer and inner door panels. The inner and outer reinforcements are applied to the belt line area of the front and rear doors to make the doors more energy absorbent. Inner and Outer Reinforcements

155BO07

Side Impact Protection Beams The cross section of the door frame has been made smaller to improve the looks. The rigidity of the area of the door frame on which the door is installed has been improved and the wind noise has been reduced by changing the shape of the frame reinforcement and adding a bracket.

A Frame Reinforcement

Bracket

A’

155BO31

155BO11

155BO12

New

Previous A – A’ Cross Section

BODY — HIGHLY RIGID BODY

124

FRAME The shape of the various areas of the frame has been modified in order to realize excellent collision safety performance, good driving stability and riding comfort. A continuous flange type construction has been adopted in the areas that join the side rails to the cross members to realize excellent joining rigidity. Similarly, the continuous flange type construction has been adopted in the areas that join the brackets.

155BO42

Continuous Flange

Cutout Flange

155BO44

155BO43

New

Previous View A

BODY — HIGHLY RIGID BODY

125

IMPACT ABSORBING STRUCTURE 1. General The impact absorbing structure of the new LX470 provides a body and frame construction that can effectively absorb the energy of impact in the event of a front, rear or side collision. Also, an excellent occupant protection performance has been realized by adopting a frame construction that effectively absorbs and disperses the impact energy, and a strong body construction has been made possible through the use of the large and optimally allocated frame materials around the cabin.

2. Construction Impact Absorbing Structure for Front Collision Corner beads have been provided in the front area of the side rail. Also, the cross section area of the side rail has been enlarged and reinforcements have been provided inside the side rail. Through these measures, the deformation of the frame can be controlled in accordance with the impact energy that is applied during a frontal collision, thus effectively absorbing the impact energy that is transmitted to the cabin and minimizing the deformation of the cabin.

Corner Beads

Reinforcement

155BO04

Side Rail

155BO05

Axial Compression Area

Plane Bend Area

BODY — HIGHLY RIGID BODY

126

Impact Absorbing Structure for Side Collision Impact energy of a side collision directed to the cabin area is dispersed throughout the body via pillar reinforcements, side impact protection beams, floor cross members, etc. This dispersion of energy keeps the energy directed to the cabin to a minimum level. As a result, the deformation of the cabin is minimized. A Head Impact Protection Structure has been adopted. With this type of construction, if the occupant’s head hits against the roof side rail and pillar in reaction to a collision, the inner ribs of the roof side rail and pillars collapses to help reduce the impact. Impact Absorbing Structure for Side Collision

155BO48

Head Impact Protection Structure

Resin Rib Resin Rib

Resin Rib

155BO49

BODY — RUST-RESISTANT BODY

127

RUST-RESISTANT BODY Rust-resistant performance is increased by using anti-corrosion sheet steel and anti-corrosion treatment by applying wax, sealer, anti-chipping paint, etc. to easily corroded parts such as the hood, doors, rocker panels, etc.

ANTI-CORROSION SHEET STEEL 2 types of anti-corrosion sheet steel are used: galvannealed sheet steel and zinc-iron alloy double layer galvannealed sheet steel. Galvannealed sheet steel is used for many inner panels and the engine compartment, etc. Zinc-iron alloy double layer galvannealed sheet steel is used for major outer panels such as the hood, doors and back door. : Zinc-Iron Alloy Double Layer Galvannealed Sheet Steel : Galvannealed Sheet Steel

155BO54

128

BODY — RUST-RESISTANT BODY

WAX AND SEALER Wax and sealer are applied to the hemmed portions of the hood, door panels, hinge and etc. to improve rust-resistant performance.

UNDER COAT PVC (Polyvinyl Chloride) coating is applied to the under side of the body. The fender apron and other parts which are subject to damage by flying stones, etc. are given a thick coating to improve rust-resistant performance. : PVC Coating Area : PVC Coating Area (Thick Coating) : Edge Seal

155BO09

ANTI-CHIPPING APPLICATION Soft-chip primer is applied to the hood. : Soft-Chip Primer

155BO10

BODY — LOW VIBRATION, LOW NOISE BODY

129

LOW VIBRATION, LOW NOISE BODY An effective application of vibration damping and noise suppresant materials reduces engine and road noise.

SOUND ABSORBING AND VIBRATION DAMPING MATERIALS Resin binding asphalt sheets and asphalt sheets are optimally allocated to reduce engine and road noise for quieter vehicle operation. : Resin Binding Asphalt Sheet : Asphalt Sheet

155BO08

Foamed material is provided inside the pillar and the roof rail and urethane pad is provided at the bottom of the pillars. As a result, the wind noise and the road noise that are transmitted to the rockers and the pillars have been reduced. : Foamed Material : Urethane Pad

155BO01

BODY — LOW VIBRATION, LOW NOISE BODY

130

CAB MOUNTING The allocation of the cab mounts have been revised and the characteristics of the rubber cushion of the cab mounts have been optimized. Accordingly, the vehicle’s riding comfort has been improved and noise and vibration have been reduced. The No. 1 mount has been changed from the share-type to the compression type. The No. 2 mount has been changed from the compression type to the share type. The remaining cab mounts use the same mounts as those of the previous model. No. 5 Cab Mounting (Free Mount Type)

No. 3 Cab Mounting (Compression Type)

No. 1 Cab Mounting (Compression Type)

155BO06

No. 2 Cab Mounting (Share Type)

No. 6 Cab Mounting (Share Type)

No. 4 Cab Mounting (Compression Type)

Rubber Cushion

155BO45

No. 1 Mounting (Compression Type)

155BO46

No. 2 Mounting (Share Type)

155BO47

No. 5 Mounting (Free Mount Type)

BODY — LOW VIBRATION, LOW NOISE BODY

131

WINDOW The fitting construction of the windshield glass and the quarter window glass has been changed. As a result, the height variance between the body and the window has been decreased, thus reducing the wind noise.

A Windshield Moulding Windshield Glass

A’

155BO30 155BO15

A – A’ Cross Section

Windshield Glass

Quarter Window Glass

Quarter Window Weatherstrip

A Quarter Panel A’

155BO16

155BO57

A – A’ Cross Section Quarter Window Glass

132

BODY — ENHANCEMENT OF PRODUCT APPEAL

ENHANCEMENT OF PRODUCT APPEAL BUMPER A one-piece resin bumper made of TSOP (The Super Olefin Polymer) that excels in recyclability is used for both the front and rear bumpers.

155BO17

Front

155BO18

Rear

Reinforcements and an absorber (foamed material) are provided in the front bumper to reduce the damage to the body during a light collision.

Front Bumper Cover

Absorber (Foamed Material)

Reinforcement 155BO50

The rear bumper step has been integrated with the rear bumper cover through composite manufacturing to improve the looks. Also, a step reinforcement has been provided inside the bumper cover to ensure the level of rigidity that is necessary when using the bumper as a step. Rear Bumper Step

Rear Bumper Cover

Step Reinforcement 155BO51

Frame

BODY — ENHANCEMENT OF PRODUCT APPEAL

133

MUD GUARD The material of both the front and rear mud guard inserts has been changed from metal to resin for weight reduction and improved corrosion resistance.

A Metal Insert

Resin Insert

155BO41

155BO40

A’

New

Front Mud Guard

A – A’ Cross Section 155BO13

B Metal Insert

Resin Insert

B’

155BO41

155BO40

New Rear Mud Guard

B – B’ Cross Section

155BO14

TAILGATE STOPPER The tailgate stopper has been changed from the folding-arm type to the cable type and a torsion bar has been provided inside the tailgate. As a result, the tailgate can be opened and closed more smoothly.

Torsion Bar

Tailgate Stopper

Tailgate Door 155BO52

BODY — ENHANCEMENT OF PRODUCT APPEAL

134

DOOR CHECK (FRONT AND REAR DOORS) The fitting construction of the door check to the body has been changed from the pin-fitted type to the bolt-fitted type. As a result, the appearance and the corrosion resistance of the area where the door check is fitted have been improved. The construction of the door check has been changed from the shoe type to the roller type to ensure the smoother operation of the door. In addition, an intermediate check mechanism to maintain the door open at the midway point has been provided for improved convenience.

Intermediate Check

Shoe

Roller

155BO39

155BO38

New

BACK DOOR LOCK The position in which the back door lock is fitted has been changed from the outside of the back door to the inside of the back door. Also, the control mechanism of the back door lock has been changed from the link type to the cable type. As a result, the appearance of the back door lock area has been improved and the ease of use of the lock control has been improved. Back Door Inner Panel

Back Door Lock

Back Door Outer Panel

Back Door Inner Panel

Back Door Outer Panel

155BO55

New

Back Door Lock 155BO56

BODY — ENHANCEMENT OF PRODUCT APPEAL

135

SEAT BELT 1. General An adjustable shoulder belt anchor is provided for the front seat and the outer seat of No.1 rear seat. The front seats are provided with an electrical sensing type seat belt pretensioner and a seat belt force limiter. The center seat of the No. 1 rear seat is provided with a 3-point ELR (Emergency Locking Retractor) seat belt.

2. Center Seat Belt of No. 1 Rear Seat General A 3-point ELR seat belt with its retractor enclosed in the seat back is provided as the center seat belt. Along with its enclosure in the seat back, the retractor has adopted a mechanism in which the deceleration sensor for activating the ELR unlocks mechanically when the seat belt is fully retracted. A reclining detection function has been adopted to constantly maintain the deceleration speed in which the center seat belt ELR activates when the seat back is reclined. Construction and Operation 1) ELR Mechanism The ELR of the center seat belt has adopted a mechanism in which the deceleration sensor for activating the ELR unlocks mechanically when the seat belt is fully retracted. As a result, the ease of tilting forward or folding the seat back has been improved. When a prescribed amount of the seat belt is pulled out, the deceleration sensor is released from its unlocked state and the ELR assumes the normal ELR operation.

Unlocked State

ELR Activation

Unlocked State

Unlocked State 155BO33

Seat Back in the Tilted Forward or Folded State

155BO34

Normal State

155BO35

Reclined State

BODY — ENHANCEMENT OF PRODUCT APPEAL

136

2) Reclining Detection Mechanism a. Construction The reclining detection mechanism consists of a retractor, a deceleration sensor for activating the ELR, a reclining detector, and a control cable that connects the deceleration sensor with the reclining detection area. The reclining detector, which is installed on the reclining inner adjuster, detects the difference in the angles of the seat back and the seat cushion. Retractor Seat Back Seat Belt Deceleration Sensor Reclining Detector

Seat Cushion

Reclining Inner Adjuster

155BO32

b. Operation When the seat back is reclined, the retractor moves along with the seat back movement. At the same time, the point on which the control cable is attached to the reclining detector rotates together with the movement of the seat back. Accordingly, the deceleration sensor that is connected to the control cable rotates, without changing the orientation of the sensor regardless of the reclining angle. Thus, the ELR activates at a prescribed deceleration rate regardless of the reclining angle of the seat back. Orientation of Deceleration Sensor

Orientation of Deceleration Sensor

Deceleration Sensor

Control Cable Seat Back

Control Cable

Deceleration Sensor

Reclining Detector

Seat Back

Reclining Detector 155BO37

155BO36

Normal State

Reclined State

BODY — ENHANCEMENT OF PRODUCT APPEAL

137

3. Seat Belt Pretensioner Construction The seat belt pretensioner consists of the pretensioner mechanism, retracting mechanism, and locking mechanism. The pretensioner mechanism consists of a gas generator, strip, clutch mechanism and etc. Seat Belt

Strip

Clutch Mechanism 155BO19

Gas Generator 1) Clutch Mechanism

The clutch mechanism consists of a clutch sleeve, clutch pin, clutch gear and etc. The clutch gear is integrated with the torsion bar and spool. The clutch sleeve has a strip wrapped around it. Normally, the clutch pin is engaged with the pin holder and chamber so that the rotation of the clutch gear is not obstructed. The movement of the strip, which is prompted by the gas that is generated by the gas generator, causes the clutch sleeve to rotate. Then, the clutch sleeve causes the clutch pin to shear off from the pin holder, causing the clutch sleeve and clutch gear to engage. As a result, the clutch sleeve and the torsion bar and spool rotate together. Clutch Pin Clutch Gear

Clutch Sleeve

Clutch Pin

Clutch Sleeve

Clutch Gear

Clutch Sleeve Clutch Pin Strip Clutch Gear 155BO21

Before Activation

155BO22

During Activation

BODY — ENHANCEMENT OF PRODUCT APPEAL

138 Operation

1) During Activation According to the igniter signal received from the airbag computer, the gas generator generates a large volume of high-pressure gas in the chamber. Then, the strip that is wrapped around the clutch sleeve expands, causing the clutch sleeve to rotate. Then, the movement of the clutch mechanism causes the clutch sleeve and the torsion bar and spool to rotate, thus taking up the seat belt.

Seat Belt Gas

Clutch Mechanism

Chamber

Strip

155BO20

2) After Completing Activation When the activation of the seat belt pretensioner is completed and the seat belt is pulled out by the movement of the occupant, the locking mechanism activates to lock the movement of the belt. Thereafter, if the force limiter activates, the seat belt is pulled out again, and the rotation of the shaft causes the strip to be taken up by the clutch sleeve.

Strip

Strip 155BO23

3) If the Activation Amount of the Force Limiter is Large If the amount of seat belt that is pulled out by the activation of the force limiter is greater than the amount of seat belt that is taken up by the activation of the pretensioner, it would prevent the strip from applying resistance to the rotation of the torsion bar. Therefore, the cutter cuts the strip. Accordingly, the force limiter can be activated, so that the seat belt’s force to restrain the occupant does not become excessive.

Strip Cutter

Cutter Strip 155BO24

BODY — ENHANCEMENT OF PRODUCT APPEAL

139

4. Seat Belt Force Limiter Construction The seat belt force limiter consists of a spool, torsion bar, locking base, and stopper. One end of the torsion bar is secured to the locking base and the other end is integrated via clutch gear with the hexagon-shaped portion of the spool. The stopper is coupled to the threaded portion of the locking base and rotates in unison with the rotation of the spool.

Stopper Hexagon-Shaped Portion

Seat Belt

Spool

Locking Base Torsion Bar 155BO25

Operation When the ELR mechanism is activated, if a force that exceeds a predetermined load is applied to the seat belt, the torsion bar becomes twisted, causing the spool to rotate and the belt to be released.

Seat Belt

Spool

Torsion Bar

155BO26

140

BODY — ENHANCEMENT OF PRODUCT APPEAL Along with the movement of the spool, the stopper moves while rotating on the threaded portion of the locking base. The twisting force that is generated in the torsion bar along with the rotation of the spool acts as a resistance against the pulling of the belt.

Seat Belt

Spool

Locking Base

Stopper Torsion Bar

155BO27

When the stopper comes in contact with the top of the locking base, the stopper will not be able to rotate any further. As a result, the spool will not rotate, thus stopping the pulling of the belt.

Locking Base

Spool

Stopper 155BO28

BODY ELECTRICAL — LIGHTING

141

BODY ELECTRICAL LIGHTING DESCRIPTION The new LX470 has the following systems: System

Headlights

Automatic Light Control System Daytime Running Light System Light Auto Turn-Off System

Interior Light Reminder System

Headlight Cleaner

Illuminated Entry System

Outline Anomalous 4-beam headlights in which the low-beam and high-beam lights are allocated independently have been adopted. The projector type headlights are used for the low beams and the multireflector type headlights are used for the high beams. For details, see the next page. In accordance with the light availability surrounding the vehicle, this system controls the headlights and the taillights to turn ON and OFF. The basic construction and operation are the same as in the ’95 LS400. When the vehicle is being driven in the daytime, this system enables the headlights to illuminate automatically at a reduced intensity. When the ignition key is turned from ON to ACC or LOCK position and the driver’s door is opened with the taillights and headlights turned on, this system automatically turns them off. The basic operation of this system is the same as in the previous model. If there is no change in the condition of the vehicle during a prescribed length of time in which any of the interior lights such as the dome light or map light illuminate, this system automatically turns OFF the interior lights. For details, see page 144. When the headlight cleaner switch is turned on while the headlights are on, this system sprays washer fluid on the headlight lenses to wash the dirt off them. This system is useful when entering the vehicle, fastening the seat belts and inserting the ignition key into the key cylinder in the dark. When any of the doors is opened, the illuminated entry system turns on the illumination lights around the ignition key cylinder, dome light (only when the control switch is at DOOR position) simultaneously and fade out in about 15 seconds.

BODY ELECTRICAL — LIGHTING

142

HEADLIGHTS 1. General Anomalous 4-beam headlights in which the low-beam and high-beam lights are allocated independently have been adopted. The projector type headlights are used for the low beams and the multi-reflector type headlights are used for the high beams. Low-Beam Headlight High-Beam Headlight A’

155BE01

155BE10

A – A’ Cross Section

2. Construction Projector Type Headlight The projector light used for the low-beam lights has the bulb located at one of the two focal points (No. 1 focus) while the beam collected at the other focal point (No. 2 focus) by the oval-shaped reflector reflects the light, projecting it forward to the projection lens. With this type of light, the effective usage range of the incident beam striking the upper reflector is wide and ensures a sufficient level of light. Compared to the ordinary semi-sealed beam type lamp, this type can be made more compact and since the beam from the source of light is concentrated in a narrower range, the amount of light leaking away from the direction of projection is small. Projection Lens

No. 2 Focus

Projection Lens

Reflector

Reflector Bulb

Bulb

No. 1 Focus 155BE03

Shade

155BE02

Side View

Top View Cross Section

BODY ELECTRICAL — LIGHTING

143

Multi-Reflector Type Headlight Conventional headlights accomplish the dispersion and distribution of light which is emitted by the bulbs through the lens cut pattern. However, with the multi-reflector type headlights, the light from the bulbs is dispersed and distributed through multiple parabolic shaped reflectors. As a result, the lens cut pattern is no longer provided in the center of the lens, thus realizing a clear look. Light Distribution Diagram Reflector (Rotating Parabolic Shape)

Reflector (Multiple Parabolic Shape)

Headlight Bulb

Lens Cut

Lens

Light Distribution Multi-Reflector Type Headlight

Light Distribution 155BE19

Conventional Headlight

155BE20

BODY ELECTRICAL — LIGHTING

144

INTERIOR LIGHT REMINDER SYSTEM 1. General The interior light reminder system provides two functions:interior light cutoff function and the door courtesy switch linked light cutoff function. The interior light cutoff function turns OFF the light main relay when the ignition switch is turned OFF and no changes have occurred in all the door courtesy light switches within 30 minutes. When the ignition switch is turned OFF and if any of the doors remain open longer than 5 minutes, the door courtesy switch-linked light cutoff function automatically turns OFF the lights that are linked to that door.

2. Layout of Interior Light Front Door Courtesy Light

Rear Door Courtesy Light Rear Room Light

Front Room Light Front Door Courtesy Light

Rear Door Courtesy Light

155BE16

3. Normal Operation The interior lights that illuminate along with the opening of the doors are listed in the table below. : ON (With Fade-Out), : ON, Interior Light Door to be opened Driver Side Front Door Passenger Side Front Door Left Side Rear Door Right Side Rear Door Back Door

Front Door Courtesy Light PassenDriver ger

Front Room Light

Rear Door Courtesy Light Left

Right

: OFF

Rear Room Light

BODY ELECTRICAL — LIGHTING

145

4. Interior Light Cut Off Function When the ignition switch is turned OFF, the instrument panel ECU monitors the condition of the door courtesy light switches and starts counting time. When 15 minutes have elapsed after no changes have occurred in any of the door courtesy light switches, the instrument panel ECU turns OFF the light main relay to cut off the current to the interior lights. As a result, the interior light turns OFF. However, the activation of this function is canceled and the time count is reset if the condition of the vehicle meets any of the items given below. The ignition switch is turned to ACC or ON position. Any of the doors is opened or closed. These functions help prevent the light from being left ON. Ignition Switch

ON OFF

Front Door Courtesy Switch

ON OFF

Rear Door Courtesy Switch

ON OFF

Fr Door Courtesy Switch / Front Room Light

ON OFF

5 Min. 5 Min.

Rr Door Courtesy Switch /Rear Room Light Door Ajar Warning Indicator Light Main Relay

ON OFF

5 Min.

ON OFF ON OFF

30 Min.

155BE11

5. Door Courtesy Switch Linked Light Cut Off Function When the ignition switch is turned OFF and any of the doors are opened, the instrument panel ECU monitors the condition of the door courtesy light switches and starts counting time. When 5 minutes have elapsed after no changes have occurred in any of the door courtesy light switches, the instrument panel ECU turns OFF the interior lights that are linked to the opening of a door. However, the activation of this function is canceled and the time count is reset if the condition of the vehicle meets any of the items given below. The ignition switch is turned to ACC or ON position. All doors are closed. In addition, while the timer is counting time, if any of the previously closed doors are opened, the timer resets itself and starts counting time. These functions help prevent the interior lights from being left ON if a door is unintendedly left open.

BODY ELECTRICAL — METER

146

METER COMBINATION METER The combination meter of new LX470 has the following features: An electronic analog meter with superb visibility and high-tech appearance is used as well as in the LS400. When the ignition switch is off, the meter panel is fully blacked out, giving a strong high-tech impression and a remote image from ordinary analog meters. An electronic twin-trip meter and an electronic odometer are used for convenience and good visibility. The meter needles are illuminated by white LEDs (Light Emitting Diode).

155BE07

A level sensor is provided in the combination meter to detect the inclination of the vehicle. This sensor prevents the fuel gauge from indicating erroneously due to the fluctuation of the fuel surface, which occurs when driving on a slope. System Diagram

Fuel Gauge

Level Sensor

Sender Gauge Vehicle Speed Signal

Combination Meter

155BE15

BODY ELECTRICAL — AIR CONDITIONING

147

AIR CONDITIONING DESCRIPTION 1. General The air conditioning system in the LX470 has the following features: An ECU-controlled, fully automatic front-and-rear air conditioner has been adopted. With this air conditioner, the temperature setting can be controlled independently at the front seats and the rear seats, thus improving the comfort of the occupants. An easy-to-use push button type front and rear heater control panels are used. A 3-flow level type heater unit, which features lower air flow resistance, is used. The construction of the evaporator, heater core, and blower fan has been changed. A sub-cool condenser, which cools the refrigerant twice, has been adopted. As in the ’98 LS400, an automatic recirculation system that automatically switches the air inlet mode according to the level of concentration of exhaust gases in the outside air, has been adopted. The construction of the rear heater unit and rear cooler unit have been changed.

BODY ELECTRICAL — AIR CONDITIONING

148 Performance

Heater

Air Ai Conditioner

Model Item Heat Output Air Flow Volume Power Consumption Heat Output Air Flow Volume Power Consumption

W (Kcal/h) (m3/h) (W) W (Kcal/h) (m3/h) (W)

New

5150 (4430) 340 195 6600 (5680) 580 270

4980 (4280) 330 180 6050 (5200) 245

New

Straight-Flow Type 216.9 140 27 (8.5 5.5 1.1) 1.8 (0.07) S80F11.5T

U-turn Flow Type 155.7 200 36 (6.1 7.9 1.4) S80F12T

158 80 (6.2 3.1)

150 85 (5.9 3.3)

Venntilat ation n and Heaaterr

Specifications

Heater Core

Blower

Model Item Type Size W H L Fin Pitch Motor Type Fan Size Dia. H

mm (in.) mm (in.)

mm (in.)

Air Condi Co dition oner

Type Condenser

Evaporator

Compressor

Size W H L Fin Pitch Type Size W H L Fin Pitch Type

mm (in.) mm (in.)

Multi-Flow Type (Sub-Cool Type) 520.8 650 16 (20.5 25.6 0.6) 3.2 (0.13) Drawn Cup Type 266.2 255 90 (10.5 10.0 3.5) 3.5 (0.14) 10PA20

3-Passage Flow 363 706 22 (14.3 27.8 0.9) 4.5 (0.18) 279 260 105 (11.0 10.2 4.1) 3.5 (0.14)

BODY ELECTRICAL — AIR CONDITIONING

149

Performance of Rear Heater and Rear Cooler

Rear Heater Rear R Cooler

Model Item Heat Output Air Flow Volume Power Consumption Heat Output Air Flow Volume Power Consumption

New

2100 (1800) 110 40 3170 (2730) 285 170

1860 (1600) 50 — — —

New

U-turn Flow Type 140 105.3 27 (5.5 4.1 1.1) 1.8 (0.07) S50FS

120 92.7 36 (4.7 3.6 1.4) 2.8 (0.11) 50F23T

120 75 (4.7 3.0)

115.3 65 (4.5 2.6)

Drawn Cup Type

—

W (Kcal/h) m3/h W W (Kcal/h) m3/h W

R r Coo Rear ooler

R r Hea Rear eater

Specifications of Rear Heater and Rear Cooler

Heater Core

Blower

Evaporator

Model Item Type Size W H L Fin Pitch Motor Type Fan Size Dia. H Type

mm (in.) mm (in.)

Size W H L

mm (in.)

159 200 90 (6.3 7.9 3.5)

—

Fin Pitch

mm (in.)

4.5 (0.18)

—

S70F12T

—

135 70 (5.3 2.8)

—

mm (in.)

Motor Type Blower

Fan Size Dia. H

mm (in.)

BODY ELECTRICAL — AIR CONDITIONING

150

CONSTRUCTION AND OPERATION 1. Front Heater Control Panel As in the previous model, an easy-to-use push button type heater control panel is used. However, on the LX470, the sizes and positions of the switches have been optimized to realize excellent ease of use. The air conditioning control panel uses an LCD (Liquid Crystal Display) panel to show the set temperature, air outlet mode and blower speed to ensure excellent visibility.

155BE09

2. Air Conditioning Unit The air conditioning unit incorporates a blower, heater and cooler units. This provides low ventilating resistance and improves quietness and performance. Blower Fan A shroud fan has been adopted for the blower fan to achieve both increased airflow and decreased noise. Along with the adoption of the shroud fan, the air inlet at the bottom of the blower unit that was provided in the previous model has been discontinued. Heater Core The flow of the heater water in the heater core has been changed from the previous U-turn flow to a full-path flow. Due to the resulting improvement in the heat exchanging efficiency of the heater core, the heater core itself could be made thinner.

155BE27

155BE26

New

BODY ELECTRICAL — AIR CONDITIONING

151

Evaporator By placing the tanks at the top and the bottom of the evaporator unit and by adopting an inner fin construction, the heat exchanging efficiency has been improved and the evaporator unit’s temperature distribution has been made more uniform. As a result, it has become possible to realize a thinner evaporator construction.

Tanks

Inner Fin

155BE05

Cross Section 155BE06

New

Cross Rib

Cross Section 155BE29

155BE30

BODY ELECTRICAL — AIR CONDITIONING

152

3. Condenser The LX470 has newly adopted a sub-cool condenser in which a multi-flow condenser (consisting of two cooling portions: a condensing portion and a super-cooling portion) and a gas-liquid separator (modulator) have been integrated. This condenser has adopted the sub-cool cycle for its cooling cycle system to improve the heat exchanging efficiency. Sub-Cool Cycle The receiver cycle of the previous condenser could not convert the gaseous refrigerant that was sent by the compressor into a completely liquefied state in the condenser. Thus, a portion of the refrigerant remained in the gaseous state as it was sent to the evaporator. In the sub-cool cycle of the sub-cool condenser that has been adopted on the new model, after the refrigerant passes through the condensing portion of the condenser, both the liquid refrigerant and the gaseous refrigerant that could not be liquefied are cooled again in the super-cooling portion. Thus, the refrigerant is sent to the evaporator in an almost completely liquefied state. Multi-Flow Condenser

Condensing Portion

Gaseous Refrigerant

Modulator

Liquid Refrigerant Super-Cooling Portion

155BE04

BODY ELECTRICAL — AIR CONDITIONING

The point at which the air bubbles disappear in the refrigerant of the sub-cool cycle is lower than the proper amount of refrigerant with which the system must be filled. Therefore, if the system is recharged with refrigerant based on the point at which the air bubbles disappear, the amount of refrigerant would be insufficient. As a result, the cooling performance of the system will be affected. For the proper method of verifying the amount of the refrigerant and to recharge the system with refrigerant, see the 1998 LX470 Repair Manual (Pub. No. RM620U).

High Pressure

NOTE:

153

Properly Recharged Amount

Point in which Bubbles Disappear Amount of Refrigerant 155BE24

4. Rear Heater Control Panel As in the front heater control panel, an easy-to-use push button type rear heater control panel is used.

155BE08

BODY ELECTRICAL — AIR CONDITIONING

154

5. Rear Air Conditioner Unit The rear air conditioner is separated into the rear heater unit and the rear cooler unit. Rear Cooler Unit

Rear Heater Unit 155BE17

Rear Heater Unit The rear heater unit is located under the front seat. The rear heater with a full-air mix type temperature control is used. Rear Cooler Unit The rear cooler unit is mounted inside the right rear quarter trim. A suction-type rear cooler unit that provides a blower fan downstream from the evaporator has been adopted to reduce noise. Rear Cooler Unit

Blower Fan

Evaporator 155BE18

6. Duct The rear cooler ducts are enclosed entirely inside the pillar garnish and the roof lining for improved looks. The blower outlet of the rear cooler is located in front of the occupants. The occupants’ comfort has been improved by directing the cool air from the front of the occupants, to their face level.

BODY ELECTRICAL — ACCESSORIES

155

ACCESSORIES DESCRIPTION The LX470 includes the accessory systems shown in the following table. System

Outline

Power Window System

This system includes “all-door one-touch auto up-and-down” and “jam protection” functions. The “all-door one-touch auto up-and-down” function enables the window of any door to be fully opened or closed at a touch of the power window switch. A “jam protection” function automatically stops the power window and moves it downward if a foreign object gets jammed in the window during one-touch auto-up operation. For details, see page 157.

Power Rear Quarter Window System

The power rear quarter window system is a system that opens and closes the rear quarter window by operating the switch.

Door Lock Control System

As in the previous model, this system has a “key-linked lock and unlock” and a “key-confine prevention” functions. The basic operation of this system is the same as in the previous model.

Wireless Door Lock Remote Control System

As in the ’98 ES300, the multi-function type wireless door lock remote control system has been adopted. This system uses a transmitter that can be used to lock and unlock all the doors, operate the panic alarm, etc. For details, see page 160.

Theft Deterrent System

As in the ’98 ES300, when an attempt is made to forcibly enter the vehicle without a key or open the hood, or when the battery terminals are removed and reconnected, this system sounds the horn and flashes the headlights and taillights for about 1 minute to alert the owner. The basic construction and operation are the same as in the ’98 ES300.

Engine Immobiliser System

This is a theft-deterrent system which disables the engine unless the ignition key used to start the engine has an ID code that matches the pre-registered code in the vehicle. The basic construction and operation are the same as in the ’98 LS400.

SRS Airbag

The SRS (Supplemental Restraint System) airbag is provided for the driver and front passenger. The SRS airbag has been designed to lessen the shock to the head and chest of the driver and front passenger in the event of a frontal impact collision as a supplement to the seat belt. A 3-sensor type airbag system is used in which the detection of deceleration during a collision as well as control of the airbag system is accomplished by the airbag sensor and front airbag sensor assembly. The basic construction and operation are the same as in the ’98 GS300/400.

Cruise Control System

Once it has been set at desired vehicle speed, this system automatically adjusts the engine throttle position to maintain the vehicle speed at the desired speed without operating the acceleration pedal. The basic construction and operation are the same as in the ’98 LS400.

BODY ELECTRICAL — ACCESSORIES

156 System

Outline

Moon Roof

The moon roof is a tilt-up and sliding type the same as in the previous model. The new LX470 has a newly provided “one-touch slide open and close function” and a “jam protection function”. For details, see page 163.

Memory System

The desired seat position can be stored (as well as tilt and telescopic steering and outside rear view mirror positions) in memory. 2 different driving positions can be memorized in the power seat ECU. The basic operation of this system is the same as in the ’98 GS300/400. However, on the new LX470, the mirror ECU controls the position of the mirrors.

Power Seat

As in the previous model, the front seats are power assisted by electric motors so that the seat positions can be adjusted easily by a simple switch operation.

Seat Heater

The seat heater system improves the comfort of the driver and the front passenger in a cold weather by heating the surface of the seats. Also, on the new LX470, the heating area of the seat cushion has been extended to the sides of the cushion.

Outside Rear View Mirror

As in the previous model, electrical remote control type mirrors provided with an internal heater, which operates in conjunction with the rear window defogger, have been adopted. Also, the LX470 provides the following new functions: the EC (electrochromic) mirror system that automatically changes the reflection rate of the mirrors, the power retraction function that retracts and reinstates the mirror bodies through a switch operation, and the reverse shift-linked mirror function that orients the driver-side and the passenger-side mirror downward when the shift lever is shifted to the R (reverse) position. For details, see page 166.

Automatic Glare-Resistant EC Mirror System

This system automatically reduces the reflection rate of the inner and outside mirrors by using an EC (electrochromic) element to dampen the bright glare of the headlights of the vehicle driving behind. The basic construction and operation are the same as in the ’98 LS400.

Garage Door Opener

A garage door opener has been adopted to operate the garage door, gate, etc. from the inside of the vehicle. As in the ’98 LS400, the garage door opener is provided in the map lamp area where it is easily accessible. The basic construction and operation are the same as in the ’98 LS400.

Seat Belt Warning System

If the driver or the front passenger has not buckled the respective seat belt when the ignition switch is turned ON, the seat belt warning system illuminates the warning light and sounds the buzzer to inform the driver and the front passenger that their seat belts have not been buckled. For details, see page 170.

Key Reminder System

It sounds a buzzer to warn the driver that the ignition key is still in the key cylinder. This helps to prevent the driver from getting locked out. The basic operation is the same as in the previous model.

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POWER WINDOW 1. General In addition to the previous one-touch auto-down function, a one-touch auto-up function has been added, thus enabling the all door window to fully close at the touch of the switch. In conjunction with this function, a jam protection function has been newly added. If a foreign object becomes jammed between the glass and the window frame during one-touch auto-up operation, this function automatically stops the power window’s upward movement and moves it downward.

2. Layout of Components The major function parts of jam protection function of the power window are shown below. Instrument Panel ECU

Key Unlock Warning Switch

Power Window Switch Power Window Regulator Assembly

155BE40

3. Wiring Diagram POWER

AM1 Ignition GAUGE Switch ALTER

Power Window Main Relay

To Instrument Panel ECU MAIN Power Window Master Switch

P/W Motor (For Driver)

Power Window Switch (For Rear Right)

P/W Motor (For Rear Right)

Power Window Switch (For Rear Left)

P/W Motor (For Rear Left)

Battery

Power Window Switch (For Front Passenger)

P/W Motor (For Front Passenger)

155BE12

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158

4. Construction Pulse Sensor and Limit Switch By way of the pulse plate that is attached to the reduction gear of the power window motor, the pulse sensor outputs a pulse signal with an amplitude that is appropriate for the rpm of the motor to the controller. In addition, a limit switch is enclosed in the reduction gear. This switch determines the neutral zone in which the jam function does not operate.

Pulse Plate

Output Pulse Signal

Power Window Motor 155BE38 155BE21

Controller Consisting of a pulse input circuit, jam judgment circuit, and motor drive circuit, the controller is integrated with the power window switch. The jam judgment circuit detects if a foreign object is jammed in the window by sensing a change in the signal that is output by the pulse sensor. Power Window Switch The power window master switch outputs control signals for the power window’s up, down, one-touch auto-up, one-touch auto-down functions to the controller.

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5. Operation Normal Operation During the normal operation of the power window, the power window motor rotates at a constant speed. Accordingly, the amplitude of the pulse signals that are output by the pulse sensor to the controller is uniform. When the controller receives pulse signals with a uniform amplitude, it determines that no jamming occurred. Thus, the controller determines the power window movement according to the signal that is received by the controller.

t1 = t2 Output Pulse Signal 155BE22

Jam Protection Operation If an object becomes jammed between the glass and the window frame during one-touch auto-up or key-off auto-up operation, the power window motor’s speed decreases ( 1 ). Accordingly, the amplitude of the pulse signals that are output by the pulse sensor to the controller increase. After the motor’s deceleration rate exceeds a predetermined value, the jam judgment circuit determines that jamming occurred. Then, the controller stops the upward movement of the window, and automatically moves the window downward so that there will be a window opening of 200 mm (7.9 in.) or more ( 2 ). The jam protection function operates only during a one-touch auto-up operation. Foreign object

Foreign Object Jammed

t1 < t2 155BE23

Output Pulse Signal NOTE:

Immediately before the window is fully closed, there is an area in which the jam protection function does not operate.

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160

WIRELESS DOOR LOCK REMOTE CONTROL SYSTEM 1. General The wireless door lock remote control system is a convenient system for locking and unlocking all the doors, at a distance. The basic construction and operation are the same as in the ’98 ES300. However, the following items have been changed in the ’98 LX470. A key-integrated type transmitter that excels in ease of use and portability has been adopted. A trunk lid open operation is not provided. A self-diagnosis function has been provided to determine if the received transmitter signal is correct. System Diagram

Key Unlock Warning Switch

Lock/Unlock Detection Signal

Door Courtesy Switch

Wireless Door Lock Beeper

Wireless Door Lock ECU

Headlight and Taillight Relay Door Lock Control Relay

Theft Deterrent ECU

Door Lock Motor

Theft Deterrent Horn

Transmitter

155BE14

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2. Layout of Components The major functional parts of the wireless door lock remote control system are shown below. Key Unlock Warning Switch Wireless Door Lock ECU

Door Lock Motor Door Courtesy Switch

Wireless Door Lock Beeper Door Lock Motor Door Lock Motor Door Courtesy Switch

155BE41

3. Construction Transmitter Along with the enlargement of the key grip, the multi-function type transmitter has been enclosed in the key grip. As a result, a transmitter with excellent portability and ease of use has been realized.

Door Lock Switch

An LED (Light Emitting Diode) is enclosed in the key grip to monitor if the battery is discharged. Door Unlock The key mold portion and the transmitter module Switch has been separated to improve their serviceability. Wireless Door Lock ECU

LED

Panic Switch

155BE13

As in the ’98 ES300, an antenna to receive the signals from the transmitter is integrated in the ECU. The wireless door lock ECU is located in the instrument panel on the driver side.

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4. Function The following table is a comparison of the functions of wireless door lock remote control system between ’98 LX470 and ’98 ES300. Function

Outline

’98 LX470

’98 ES300

All Doors Lock Operation

Pressing the “door lock” switch of the transmitter locks all doors.

Driver’s Door Unlock Operation

Pressing the “door unlock” switch of the transmitter once unlocks only the driver’s door.

All Doors Unlock Operation

Pressing the “door unlock” switch twice within 3 seconds opens all doors after opening the driver’s door.

Trunk Lid Open Operation

Keeping the “trunk lid opener” switch of the transmitter pressed longer than 0.8 seconds opens the trunk lid.

—

Panic Alarm Operation

Pressing the “panic” switch of the transmitter activates the alarm of the theft deterrent system (to sound the horn and flash the headlights and taillights).

Operation Verification Beeper Function

When the transmitter is used to lock or unlock the doors, this function sounds the beeper to inform that the operation has been completed.

Operation Verification Light Function

When the transmitter is used to lock or unlock the doors, this function flashes the parking lights and taillights to inform that the operation has been completed.

Auto Lock Function

If none of the doors are opened within 30 seconds after they are unlocked by the wireless door lock remote control, all the doors are locked again automatically.

Transmitter Switch Misoperation Prevention Function

When an ignition key is in the ignition key cylinder or any of the doors is not closed completely, the wireless door lock remote control is temporarily cancelled to prevent misoperation.

Repeat Function

If a door is not locked in response to the locking operation of the transmitter, the wireless door lock ECU will output a lock signal once after 2 seconds.

Door Ajar Warning Function

If any door is open or ajar, pressing the “door lock” switch of the transmitter will cause the beeper to sound.

Beeper Volume Control Function

The beeper volume can be adjusted by adjusting the wireless door lock beeper controller.

—

Security Function

Send an operation signal as a rolling code.

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MOON ROOF 1. General The moon roof in the new LX470 has the following features: A tilt-and-slide type power moon roof with “one-touch operation” and “jam protection” functions has been adopted. The “one-touch operation” function enables the moon roof to effect a fully open or a fully closed tilt-andslide operation. The “jam protection” function detects if a foreign object gets caught while the moon roof is closing (in the slide-close mode). The sliding roof microcomputer and the sliding roof motor have been integrated to reduce the number of components.

2. Layout of Components Sliding Roof Glass

Tilt Switch

Sliding Roof Control Computer Sliding Roof Motor

Rail Slide Switch

Drive Cable 155BE31

155BE32

3. Wiring Diagram Power Source Circuit

Sliding Roof Control Computer

From Battery Moon Roof Switch

Sliding Roof Motor Courtesy Switch (Driver’s Door)

Hall IC

Limit Switch

155BE36

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4. Construction Sliding Roof Drive Gear Assembly The sliding roof drive gear assembly consists of a microcomputer that contains a Hall IC and a drive unit that contains a sliding roof motor and a drive gear. The sliding roof drive gear assembly contains a pulse sensor to detect if any foreign object gets caught in the sliding roof. The pulse sensor consists of a magnet and a hall IC. The magnet rotates with the sliding roof motor. The hall IC detects a polarity change which is caused by the rotation of the magnet, and converts it into a pulse signal. The pulse sensor (hall IC) outputs a pulse signal to the microcomputer. Sliding Roof Motor

Sliding Roof Control Computer

Output Pulse Signal

Drive Gear Assembly

155BE38

155BE39

5. Operation One-Touch Operation When one of the moon roof switches (the slide switch or the tilt switch) is pressed longer than 0.3 seconds, the microcomputer causes the sliding moon roof motor to rotate in accordance with the switch operation. At the same time, the timer function in the microcomputer activates, allowing the current to be applied to the motor even if the finger is released from the switch. Thus, the moon roof will carry out the slide-open, slide-close, tilt-up, and tilt-down operations even if the switch is no longer pressed. The one-touch operation stops its operation when one of the conditions given below is met. The microcomputer determines that the motor has seized (by the activation of the “jam protection” function), according to the signals from the Hall IC. The moon roof fully opens or fully closes during a tilt-up or down operation or a slide-open or close operation. One of the moon roof switches (the slide switch or the tilt switch) is pressed during the moon roof operation. The slide switch and the tilt switch are turned ON simultaneously.

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Jam Protection Operation If an object becomes jammed between the moon roof and the body during slide close operation, the sliding roof motor’s speed decrease ( 1 ). Accordingly, the amplitude of the pulse signals that are output by the pulse sensor to microcomputer increases. When the motor’s deceleration rate exceeds a predetermined value or the seizure of the motor is detected, the microcomputer determines that jamming has occurred. Then, the microcomputer stops the close movements of the moon roof, and automatically moves the moon roof open. If jamming occurs during a slide-close operation, the moon roof slide opens until the roof opening is 200mm (7.9 in.) or more. ( 2 )

Foreign Object Jammed 1

Sliding Roof Glass

t2 t1 < t2 155BE23

Foreign Object Slide Operation

155BE34

Output Pulse Signal

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OUTSIDE REAR VIEW MIRROR 1. General In addition to the power remote control mirrors with an internal heater that are used on the previous model, the outside rear view mirrors provide the following new functions: the power retraction function, reverse shift-linked mirror function, and the EC (electrochromic) mirror system. The power retraction function retracts or reinstates the mirror by operating the power retraction switch. The reverse shift-linked mirror function automatically orients the driver-side and the passenger-side mirror downward when the shift lever is shifted to the R (reverse) position, provided that the mirror control select switch is set to the driver side. The EC mirror system automatically changes the mirrors’ reflection rate.

2. Wiring Diagram

Battery

Ignition Switch Rear View Mirror (Left Side)

Reverse Switch

Mirror ECU

Rear View Mirror (Right Side)

Mirror Switch 155BE37

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3. Power Retraction Function Construction 1) Outside Rear View Mirror A photo coupler for detecting the seizure amperage has been adopted in the power retraction system to ensure a compact retraction unit. 2) Retractable Switch The retractable switch is located on the left of the instrument panel, together with the mirror control switch. The retractable switch is a lock type switch.

Retractable Switch

155BE25

Operation When the ignition switch is in the ACC or ON position, operating the retractable switch causes the mirror to retract or reinstate. If the ignition switch is turned OFF during the retraction or reinstating operation, the mirror immediately stops its movement. Then, when the ignition switch is turned back to the ACC or ON position, the mirror will resume its retraction or reinstating operation. If the setting of the retractable switch and the position of the mirror do not match (e.g., the retractable switch is set to the retraction side while the mirror itself is in its extended state), turning the ignition switch to the ACC or ON position will cause the mirror to retract or reinstate in order to match the setting of the retractable switch.

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4. Reverse Shift Linked Mirror Function Construction 1) Park/Neutral Position Switch The park/neutral position switch detects that the shift lever has been shifted to the R (reverse) position. 2) Mirror Control Select Switch When the shift lever is shifted to the R (reverse) position, operating the mirror control select switch turns the reverse shift-linked mirror function ON/OFF.

Mirror Control Select Switch

155BE25

3) Outside Rear View Mirror When the shift lever is shifted to the R (reverse) position and the mirror control select switch is changed to the LH position, vertical motor orients the mirror downward. 4) Mirror ECU Upon receiving the signals from the switches, the mirror ECU controls the dedicated motor for the reverse shift-linked mirror function.

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Operation 1) Downward Operation The reverse shift-linked mirror function activates when the signals from the switches listed below are input into the ECU, allowing the motor to orient the driver-side and the passenger-side mirror downward in accordance with the signal from the mirror ECU. The ignition switch is ON position. The shift lever is shifted in the R (reverse) position. The mirror control select switch is changed from the neutral position to the LH (driver side) position. 2) Reinstating Operation The mirror that is oriented downward by the reverse shift-linked mirror function becomes reinstated to the position before the reverse function was activated if any of the conditions listed below is met: The shift lever is shifted to any position other than the R (reverse) position. The mirror control select switch is changed to the neutral position or the RH (passenger side) position.

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SEAT BELT WARNING SYSTEM 1. General In the seat belt warning system of the previous LX450, if the driver does not wear the seat belt when the ignition switch is turned ON, the warning light illuminates and the buzzer sounds for several seconds to inform the driver that the seat belt has not been worn. However, on the new LX470, this system has been changed as described below. The method for indicating the seat belt warning light for the driver has been changed from the illuminating type to the flashing type. A seat belt warning for front passenger has been newly provided in the center cluster. When the front passenger seat is occupied but its seat belt is not being worn, this function flashes a warning light to inform the front passenger that the seat belt is not being worn.

2. Seat Belt Warning for Front Passenger Construction The seat belt warning for the front passenger consists of the front passenger seat belt buckle switch, occupant detection sensor, seat belt warning light for the front passenger. 1) Belt Warning Occupant Detection Sensor The occupant detection sensor, which is enclosed in the seat cushion of the front passenger seat, is used to detect whether or not the front passenger seat is occupied. This sensor, which is shaped as illustrated below, consists of a construction in which two sheets of electrodes sandwich a spacer. When the occupant is seated, the electrode sheets come in contact with each other through the hole that is provided in the spacer portion, thus enabling the current to flow. Thus, the sensor detects whether or not an occupant is seated in the front passenger seat. Spacer

Electrode Sheet

Electrode Sheet Sensor OFF

156BE19

Occupant

Occupant Detection Sensor

156BE18

Sensor ON

156BE20

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2) Front Passenger Seat Belt Buckle Switch The front passenger seat belt buckle switch is enclosed in the seat belt buckle of the front passenger seat to detect whether or not the seat belt for the front passenger is being worn. 3) Seat Belt Warning Light for Front Passenger The seat belt warning light for the front passenger is located in the display of the center cluster. This light flashes to warn if the front passenger does not have the seat belt buckled.

Seat Belt Warning Light for Front Passenger 155BE42

Operation When an occupant is seated in the front passenger seat, the occupant detection sensor activates, thus enabling the system to recognize that the occupant has seated. When the ignition switch is turned ON, a warning light flashes if the front passenger is not wearing the seat belt. The warning light continues to flash until the front passenger wears the seat belt. If the front passenger seat is not occupied, the warning light remains extinct regardless of the condition of the seat belt.

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APPENDIX

MAJOR TECHNICAL SPECIFICATIONS Area

Item

Wagon

Vehicle Grade Model Code

— UZJ100L-GNPGKA

Length

mm (in.)

Wide Height*

mm (in.) mm (in.)

Front Rear Front Rear

mm (in.) mm (in.) mm (in.) mm (in.)

Effective Leg Room

Front Rear

mm (in.) mm (in.)

Shoulder Room

Front Rear

mm (in.) mm (in.)

Length

mm (in.)

Wide Height Front Rear

mm (in.) mm (in.) mm (in.) mm (in.)

Min. Running Ground Clearance

mm (in.)

Angle of Approach

degrees

Overall Wheel Base Tread

Major Dimensions & Vehicle Weights

Effective Head Room

Cargo Space

Overhang

mm (in.)

Angle of Departure Curb Weight

Gross Vehicle Weight

Front

degrees kg (lb)

Rear Total Front Rear

kg (lb) kg (lb) kg (lb) kg (lb)

Total kg (lb) Fuel Tank Capacity L (US.gal., Imp.gal.) Luggage Compartment Capacity m3 (cu.ft.) Max. Speed km / h (mph)

Performance

Max. Cruising Speed Acceleration

Max. Permissible Speed Turning Diameter (Outside of Front)

km / h (mph) 0 to 60 mph sec. 0 to 400 m sec. 1st Gear km / h (mph) 2nd Gear km / h (mph) 3rd Gear km / h (mph) 4th Gear km / h (mph) Wall to Wall m (ft.) Curb to Curb

m (ft.)

Engine Type Valve Mechanism

Engine Electrical

Engine

Bore Stroke Displacement

mm (in.) cm3 (cu.in.)

Compression Ratio Fuel System Research Octane No. RON Max. Output (SAE-NET) kW / rpm (HP@rpm) Max. Torque (SAE-NET) N.m / rpm (lb-ft@rpm) Battery Capacity (5HR) Voltage & Amp. Hr. Generator Output Starter Output

Watts

Clutch Type

Transmission Gear Ratio

In First In Second In Third In Fourth

Suspension Type Stabilizer Bar

Front Rear Front

Rear Steering Gear Type Steering Gear Ratio (Overall) Power Steering Type

1016 (40.0), 993 (39.1)*2 1003 (39.5), 988 (38.9)*2 1074 (42.3) 870 (34.3), 752 (29.6)*3 1558 (61.3)

1552 (61.1) 1176 (46.3) 1081 (42.6) 1002 (39.4) 895 (35.2) 1145 (45.1)

250 (9.8) 30° 23° 1260 (1605) 1190 (955)

2450 (2560)

3110 (3495) 96 (25.4, 21.1) — 175 (109) 140 (87) 9.9

17.6 24 (15)*4, 60 (38)*5 44 (28)*4, 110 (69)*5 68 (43)*4, 168 (105)*5 —

12.7 (41.7) 12.1 (39.7) 2UZ-FE 32-Valve, DOHC 94.0 84.0 (3.70 3.31) 4664 (284.5)

9.6 : 1 SFI 96 172/4800 (230@4800) 434/3400 (320@3400)

12-64, 60*6 1200 2.0 55

— 2.393

Differential Gear Ratio (Front/Rear)

Brake Booster Type Proportioning Valve Type

2850 (112.2) 1620 (63.8) 1615 (63.6)

1.531 1.000 0.753

In Fifth In Reverse Transfer Gear Ratio H4/L4 Differential Gear Size (Front/Rear) Front Brake Type Rear Parking Brake Type

4890 (192.5) 1940 (76.4) 1850 (72.8)*1

— A343F 2.804

Transaxle Type

Chassis

U.S.A. and Canada

Body Type

in.

1.000/2.488 4.300/4.300 8”/9.5”

Ventilated Disc Ventilated Disc Drum Hydraulic P & B Valve Double Wishbone

4-Link with Lateral Rod STD STD Rack & Pinion 19.8

Integral Type

* : Unladed Vehicle *1: Vehicle Height Normal Position *2: With Sun Roof *3: Center Seat *4: Transfer in Low *5: Transfer in High *6: Option