Mastertech Auto Repair

Forward-Vehicle involved-2005 Jeep Grand Cherokee, 5.7

About me – Retired now but x-auto-mechanic; have been working on and with all types of vehicles since the ‘80s, so my extensive experience is of great value to me when it comes to knowing another credible auto-mechanic.

Early Sept 2021, we began experiencing new issues with this vehicle, in short: 
1. The throttle acceleration would sporadically jump (as if one was to tap the gas pedal on and off) and then for no reason, die.
2. The vehicle would die unexpectedly no matter speed or angle.
3. Would not hold a steady idle.

I used a consumer model code reader to see if I could determine the possible issue and resolve it myself, knowing how expensive it is these days for auto-repair, especially if it involved troubleshooting/replacing electronic components. I did retrieve some codes ex: U1411 which indicated the likely cause was the ECM. Well, I also happen to know the ignition switch could cause the vehicle to unexpectedly die so I changed that component first. It’s an easy replacement and an inexpensive component ($30) but a little tedious to replace for most that are not mechanically inclined; however that did not resolve the issue.
I researched for about 4 hours in addition to speaking to a couple of 30+ year ASE Certified Jeep mechanics who, after reviewing everything were very confident it was the PCM and not the ECM. That said, other than locating one from a salvage yard, the PCM ($1,300) was no longer available for this vehicle nor was the ECM which would have been considerably less.
After speaking to John (Owner of “MasterTech Auto Repair”) in Harrison, AR. and describing the issues, he assured me he had much more sophisticated equipment to perform a more in-depth diagnosis. He was relatively confident that he would be able to determine the issue fairly quickly over a few days.

So that was the best and most effective way forward to determine what the issue was. After a few days of diagnostics/graphs and research, John updated us indicating although right now he was leaning towards the ECM being the issue, he only felt 75% confident. He also mentioned he was noticing some fluctuating voltage in the throttle body. In any case, he wasn’t satisfied just yet and asked if it would be OK for him to continue his deep diagnostics and troubleshooting until he felt confident of the cause. I told him to keep it and do what he needed to do until he felt absolutely confident of his diagnosis because I wasn’t going to spend money on an ECM or PCM if that didn’t resolve the issue and he completely understood. So, 2 more days went by and we received an update call from John. After even more graphing and diagnostics and personal persistence, John said he was now absolutely confident the issue was in fact the throttle body.

All in all, after previously conferring with other long-tenured ASE certified Jeep mechanics, their recommendations could have cost us upwards of $1,500-2,000+, and instead, the decision to take it to MasterTech Auto Repair was the correct choice and most affordable and effective choice and resulted in the complete satisfaction of this customer all due to John’s steadfast insistence not to be partially satisfied but to be absolutely satisfied with a cause and resolution.

Readers Note: Coming from a family of Auto and Aircraft Mechanics, I am not easily pleased nor satisfied when it comes to dealing with most people who claim to be auto-mechanics b/c most don’t know anywhere near what they claim to know. Dealing directly with John at MasterTech was a very nice and refreshing experience and I personally and HIGHLY recommend them to anyone.