Emissions
The best tools in your arsenal are your sense of smell, your sight and your ears
W By Edwin Hazzard
When a vehicle comes into your service bay with a drivability problem you immediately start to wonder if this is could an ignition problem, a fuel problem or some kind of electrical issue that’s happening that would make this vehicle act up enough for the customer to bring it into your shop. As vehicle technology has changed drastically over the years, there are still some things you have to remember that haven’t changed. Even though the internal combustion engine platform has evolved over the years, the same basic principles have stayed the same. The same old adage is true. Every four stroke engine is the same. They perform intake, compression, power and exhaust. No matter what the problem could be with an engine that has a drivability-related issue, the mechanical integrity has to be working absolutely correct. This is especially important on today’s engines that have a control module keeping an ever watchful eye on any problems that could crop up. When I go into a shop to perform a diagnostic repair I try to give the technicians who are with me an impromptu training class. One of the things that I like to drive home is the fact that if it’s a drivability problem we will know that no matter what the culprit is that is causing the issue, it can be said that there are only four possibilities that we have to look at. It can be a mechanical problem, an electrical problem, a fuel
38
ASP
December 2019
Figure 1: A turbo charger on a 2019 Chevrolet Traverse. problem or an ignition problem. That’s it. Those are your only choices. The fun starts when it could be more than one of those four scenarios at the same time! Determining the issue is what makes a service technician a drivability technician. Figuring out how to put together a diagnostic game plan and applying that to pinpoint the problem is what separates a good technician from an elite technician. In this article I will show you an easy way to help you tackle some of these tough drivability problems that can arrive in your service bay.
Emission issues
One of the issues that can crop up on a tough diagnostic job is finding out that the cause can be from an emissions-related problem. As you are aware, vehicle design evolution has incorporated multiple emission monitoring and control devices to control the air pollution problems that we have faced over the last three or four decades. Unfortunately, while they are good for our at-
ALL PHOTOS COURTESY OF SOUTHEAST MOBILE TECH
TROUBLESHOOTING EXHAUST EMISSIONS
