Speakers Information- Controls, Measurement & Calibration Congress
Automatized System of Electrical Diagnosis Validation Andre Luis Furlanetti Gouvea Magneti Marelli Sistemas Automotivos
Alexandre Maria Alexsandro da Silva Priscilio Roberto de Almeida Magneti Marelli Sistemas Automotivos
ABSTRACT The present article is regarding an “Automatized System of Electrical Diagnosis Validation”, developed to perform the electrical tests in a vehicle (among the actuators and sensors and the vehicle ECU) during the OBD1 calibration or validation phase. This system will replace the manual validation, performed since the beginning of electronic Injection.
INTRODUCTION The vehicular electrical validation began when with the beginning of electrical injection, when the vehicle was received many sensors and actuators. It was necessary to check if any sensor or any actuator doesn’t work as well, because in case of failure, all injection system could be damaged. At the beginning, all tests were performed manually one by one using a break-out box (picture 01) with jumpers or switches to make the open circuits between the sensors and vehicle ECU or between the actuators and ECU. Similarly when was necessary to make a short circuit to positive voltage or short circuit to negative voltage. Also, all known break-out box weren’t immune to external interference or external noise, sometimes they were old and hand crafts devices. In addition, all others tests as congruence values or intermittent signals were made with considerable difficulty.
picture 01 – break out box
MAIN SECTION As the electrical diagnose validation procedures are based in ODB rules, are need to perform them during all phase of software development, to guarantee the diagnose function.
So it is necessary to start and stop the engine many times until detect the failure simulated. As this procedure was done manually, many times we have different acquisitions, because the human control isn’t accurate. For these points and others, the proposal system was developed. Based on the ETAS equipment, and some others internally developed devices, we can through a Matlab script or Excel VBA script, command the engine, the calibration, the measurement and the acquisition without applicator engineer interference. Firstly the vehicle receives the development ECU, with this kind of ECU we can read directly of our own electronic injection software. It is very important during the error simulation to read engine and vehicle parameters like: -
Engine Speed
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Intake Manifold Air Pressure
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Intake Manifold Air Temperature
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Engine Coolant Temperature
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Engine Oil Temperature
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Engine Oil Pressure
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Spark Plug timing
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Battery Voltage
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Vehicle Speed
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Accelerator Pedal Position
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Throttle Body Position
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Engine Camshaft
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Lambda Oxygen Sensor
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MIL Status
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KL15
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Etc…
But for each kind of failure, also need to read specific parameters: -
Threshold to function
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Specific failure status
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System control mode
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Specific counters
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PCODES
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FREEZE FRAMES
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Etc…
As the our electronic injection system is based on ECU with ETAS ETK, the interface with the Applicator Engineer is with software INCA, where the electronic injection calibration software could be read, written, changed and recorded. when the job is manually, it is necessary interact with INCA during all time asking to read, changing values, recording, saving, etc. (picture 02).
Picture 02 – example of Experiment INCA. The failure simulation also need total interaction during the validation process. Better than a craft break-out box we are using the Fault Insertion tool from Etas, the ES4440 (picture 03, picture04 ), commanded by own Etas software Labcar Pin Controll. (picture 05).
Picture 03
Picture 04
Picture 05
To transform the manual operation system in automated system, some steps that before were done by applicator engineer, like a turn ignition ON or Off, start vehicle engine, select failure, chose the voltage to short circuit now need to be automated with Matlab script assist. For this issue, through a Matlab script, we can: -
Open the INCA software
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Select the vehicle calibration
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Open the specific experiment
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Select all parameters that we need
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Start acquisition recorder
Also with that script we can command the Fault Insertion Tool: -
Select the vehicle ECU pin,
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Select the failure (short circuit to positive voltage, open circuit, etc.)
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Select intermittency (if necessary)
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Start Failure
With this procedures, the electronic injection software, during its normal function can detect that failure generated, at this moment to validate that failure, the engine vehicle need to perform three drive cycles (a complete ignition ON, engine ON Ignition OFF and engine OFF). With same script, through a Etas equipment ES930 (picture 06) connected though vehicle interface (picture 07) at KL15 and at engine starter, the automated system can perform. -
KL15 ON
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Engine ON
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(wait for the electronic injection software detect the generated failure)
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KL15 OFF (the engine is turn off in same time)
After three complete drive cycles, the failure can be reset and others three drive cycles are needed to healing the failure. So the “Automatized System of Electrical Diagnosis Validation�, is physically composed of ES4440 (Failure insertion tool) ES592 (ECU interface), ES930 (Hardware output device) and a vehicle interface (Magneti Marelli internal device), (picture 08). But there is a logical part associated with the project: the Matlab script and INCA software.
Picture 06 – ES930
Picture 07 – Vehicle Interface
Picture 08 – Setup in vehicle
CONCLUSION With this automated system we can perform all electronics diagnose tests with save of time, repeatability (regardless the vehicle manufacture) and standardization. The reports can be optimized with graphs from Matlab.
ACKNOWLEDGMENTS I would like to thank: The OBD1 Magneti Marelli Powertrain Group (Mr. Maria, Mr. Silva, Mr. Almeida). the staff Etas Brazil (Mr. Godoy, Mr. Manguino and Mr. Kawamoto).
DEFINITIONS, ACRONYMS, ABBREVIATIONS ECU – Vehicular Electronic Control Unit ETAS – Germany company ETK – External Memory to running the Electronic Injection software inside ECU. FREEZE FRAMES – Snapshots at moment that error occur INCA – Integrate Calibration and Acquisition System, ETAS KL15 – Ignition Key MIL – Malfunction Indicate Lamp OBD – On Board Diagnose OBD1 – Electronic On Board Diagnose PCODES – Standardization Failure codes (OBD) VBA – Microsoft Visual Basic for Excel