Save Time Diagnosing with Real-world Insights

There are times when a perfectly logical diagnosis just isn’t enough to fix the vehicle in your bay.

Help-iconYou have probably encountered a vehicle that defied logic and experience, where you needed a little help from your fellow service professionals to get to the heart of an issue. This common scenario is being transformed by repair information systems that deliver real-world insights from professional techs right alongside OEM specs and procedures.

Here’s an example of how this scenario might play out: A 2005 MINI Cooper 1.6L S pulls into your shop with the check engine light on. Upon reading the code, you find a P1688 – electronic throttle control monitor level versus mass airflow calculation. The code set condition is because the flow of air going through the mass airflow sensor (MAF) is different from the flow of air going into the throttle body.

Where to start with the diagnosis? Well, common sense and experience might lead you to the MAF, suspecting a faulty sensor. This makes perfect sense most of the time, but not in this particular vehicle. And this is where real-world knowledge can keep you from wasting time and going down the wrong diagnostic path.

Instead of picking up the phone to consult with a colleague, a little research will reveal the actual root cause of the problem. When you look up the P1688 code in Mitchell 1’s ProDemand, the SureTrack diagnostic module provides a Common Replaced Parts Graph based on real experience in the aftermarket. The graph shows you that for this vehicle, the harmonic balancer is much more likely to be the main culprit.

Click image to expand to full size

Click image to expand to full size

In addition to common replaced parts, you also find a “Real Fix” for this issue — a nugget of insight based on actual repair orders and experiences from other expert technicians. The Real Fix gives you a lot of valuable information presented in a concise Complaint-Cause-Correction format (see figure) that guides you to an accurate diagnosis.


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After verifying the customer’s complaint and the code, you discover that the cause of the issue is very likely to be the crankshaft pulley that has separated from the harmonic balancer. The damaged crankshaft pulley caused the digital electronics module (DME) to miscalculate the vehicle’s engine speed, which caused the DME to miscalculate the engine load parameter and set the trouble code.

So, with this information in hand, you feel confident in replacing the harmonic balancer. Then you verify the repair: the vehicle operates properly, with no check engine light illuminated and no fault codes. Success!

What is the lesson? Real-world information is essential in diagnosing and repairing today’s vehicles. ProDemand groups its Real Fix content by “probable component,” giving you flexibility to search the most common fixes first, or if you are more interested in “rare fixes,” you can also invert the list and show the least common fixes first, making it quick and easy to find what you need.

In the case of the 2005 MINI, the Real Fix in ProDemand pointed you in the correct diagnostic direction from the very start, saving you time and keeping you on schedule with the repair.

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About the Author

Gary Hixson

Gary Hixson is a Sr. Market Manager at Mitchell 1, and is responsible for product and market management of the Repair Information product line. Most recently he managed the release of ProDemand™, the industry-leading repair, diagnostic and maintenance information system.