Automotive CSI

Sept. 29, 2021
Having trouble developing your diagnostic process? Try this approach!

As many of you know, Motor Age and TST (tstseminars.org) have partnered for the last decade to bring you a special webinar presentation every quarter. This year, we have been extremely fortunate that each has been sponsored, allowing us to offer it to you at no cost. We hope the trend continues!

Our August webinar was entitled “The Top 10 DTCs: What to do when they show up in your shop!” And as the title implied, we counted down the most common DTCs technicians deal with. One of the interesting articles I read while preparing for the webcast reported on the most common repairs made related to check engine light concerns. Some of the items on the list made me think about the increasing dependence on databases like these as a primary diagnostic tool. The result is an often unnecessary and potentially expensive repair that doesn’t correct the problem. If you’re a tech who uses the results of these databases as a “shopping list” rather than an informational resource, this column is for you!

The positives

Now, don't get me wrong. When I first started in the business, we didn't have the internet to rely on. We did, however, have other shops near us and we would often share our experiences to help us find the solution to a stubborn concern. Most of us knew the common issues suffered by the models of the era, but the term “pattern failure” or “silver bullet” wasn't yet in use.

Today, a variety of companies, including OEMs, collect vehicle data and compile it into service databases. You likely use one of these sources of information in your shop today! This is the equivalent of every shop in the country comparing experiences with one another, and it can quickly identify pattern failures among makes and models. This data can be a useful bit of diagnostic information, helping you more quickly isolate the cause of your customer’s concern if used properly.

The negatives

Like any tool, vehicle repair databases can be used correctly or incorrectly. Unfortunately, it seems that all too often this data is used to bypass a true diagnosis in favor of just working down the list of the most common causes of the customer’s concern until the car is either fixed or the customer decides to take the problem somewhere else. Don’t believe me? Just take some time to read the posts in many of the automotive groups on a social platform like Facebook, and you’ll soon see several requests from techs that read something like this:

“Hey, guys! I have a [INSERT CAR MAKE AND MODEL HERE] with a terrible misfire at idle. Anyone know what the problem is?”

OK, it isn’t always that succinct, but it is also not uncommon for techs (both professional and DIY) to look for the easy answer. They tend to do so without putting in any of the effort a true professional tech would. A professional tech would seek to ensure he or she fixes his customer’s problem correctly, the first time out and proven with proper testing. Now, DIYers I can forgive, but anyone who charges for this charade and (even worse) continues to fire the “parts cannon” at the problem hoping to find the right fix (while charging the customer for every “shot” fired) has no right to consider themself a professional.

Often, shops that operate on this principle make more money in the end than the shop with the technician who ultimately diagnoses the problem correctly and finally fixes the car. Yes, the first shop loses the customer, and the second gains one, but the reality is there are enough customers to keep the first shop going. I pray their lack of ethics and professionalism is exposed and they get run out of town on a rail. They are only continuing the stereotype that so many consumers still have of us. And if that stereotype continues to go unchecked, it will remain difficult (for those committed to doing the job right) to justify the fees that this level of dedication and professionalism deserves.

Want to be more professional?

To be honest, I know in my heart that most techs in this country don’t want to fall into the category of “parts changer.” I know the boss is on your back to get the car fixed and gone, and the customer may be just as impatient. The reason you fall into this cycle is most likely a lack of training and/or experience. It's not that the training opportunities don't exist. Heck, since the pandemic, sources of online virtual training have exploded. The problem is that the techs who need it the most don't know of these opportunities or, in some instances, can't afford them.

There are more than 75,000 automotive technicians in this country alone. Here, at Motor Age, we pride ourselves on the number of them we reach but the reality is that there are still thousands of techs who don't even know who we are (yet)! Imagine, then, how hard it must be for the various training providers to get their offerings in front of the men and women who need them the most.

If you’re new to Motor Age, I encourage you to sign up for our newsletter(s) so that you will be informed of these opportunities as they come to our attention. Take advantage of every opportunity you can — online or in person. Seek out like-minded techs and grow your skills together, help one another, and set the pace for others to follow.

Another step you can take is to modify your diagnostic cycle; think like a detective. An effective diagnostic approach is not too different from the investigative techniques used by law enforcement to identify their suspect.

While I don’t have the space to detail the process here, you can watch the August webinar by logging on to https://events.motoragetraining.com/products/Top-10-DTCs.aspx and setting up your Motor Age Training account. While you’re there, take a look around at all the various resources we have for you — all designed to help you take your skillsets to the next level.

Here are the basics:

First, investigate the crime scene. This means gathering as much information as you can about the customer’s concern and includes things like customer interviews, retrieving related Diagnostic Trouble Codes (DTCs), and understanding the operation of the system affected. The more time you spend developing your customer’s victimology the less time you’ll spend catching the cause!

Second, remember that everyone is a suspect. All too often, techs (yours truly included) fall into the trap of ruling out a possible cause before proving it as an unlikely cause. We eliminate it just because we don’t think it could be related. Guess what? The overlooked candidate is often the cause of the complaint you’re trying to solve!

Third, begin eliminating suspects through general testing. This involves the use of testing techniques that will eliminate numerous possibilities at once. For example, a relative compression test with a cylinder ignition reference can help you identify an engine mechanical problem or timing problem in a few minutes, eliminating the need to test the fuel and/or ignition systems.

Fourth, as your suspect pool shrinks, begin eliminating individual items on your list. This is what my friend Jim Morton refers to as “pinpoint” testing. In the case of the engine mechanical fault (we discovered in our relative compression test), the next step might be an in-cylinder pressure test to isolate the cause to the valvetrain or rings.

Fifth, once you think you've identified the cause, perform one more test to verify your conclusion.

Sixth, complete the repair and repeat the tests to confirm your fix.

Last, verify that your customer’s concern has been solved. This is an important step that is different from the last one (you may have found “a” problem, but not the “only” problem contributing to their actual complaint).

Learning a repeatable, dependable diagnostic process takes time, but it is not impossible. Learning the testing techniques needed to isolate your suspects is also time-consuming but easier than ever. Invest the time today and you’ll find yourself becoming more efficient and more accurate in the repairs you make — and that means a fatter paycheck!

About the Author

Pete Meier | Creative Director, Technical | Vehicle Repair Group

Pete Meier is the former creative director, technical, for the Vehicle Repair Group with Endeavor Business Media. He is an ASE certified Master Technician with over 35 years of practical experience as a technician and educator, covering a wide variety of makes and models. He began writing for Motor Age as a contributor in 2006 and joined the magazine full-time as technical editor in 2010. Pete grew the Motor Age YouTube channel to more than 100,000 subscribers by delivering essential training videos for technicians at all levels. 

Connect with Pete on LinkedIn.

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