My wife has a 2006 Jeep Wrangler X that has a 4.0L V6. Automatic transmission. ~74K miles. I apologize for the lengthy post.
In November, we had a CEL come on and the car went into 'limp mode.' We were getting the code P0750 which is the 'Shift Solenoid A' code. After perusing some of the discussions on this site, I felt comfortable enough to replace the part myself in an effort to save a few bucks. I installed the part and the Jeep was up and running again with no codes. This fixed lasted exactly 1 month. In the middle of about a 60 mile trip, her light came on once again and the car again showed the same symptoms.
Having vowed to never open up another transmission unless it was life or death, we took the car to a transmission shop. He insisted that the Jeep was in need of fresh new shift solenoid pack, despite me telling him that I had done the same just a month earlier. But I understood his need to go through the protocols and explore the most obvious solutions first. He changed the part and it did not work. After a few other checks (he didn't really tell me what he did), he determined that I need a transmission rebuild. Having just had the most expensive diagnosis thrown at me possible (~$2000), the one thing that I was sure of, was that I needed a second opinion.
After gathering recommendations, we took it to a new shop. He hooked us up and to our surprise, we were now getting the generic, P0700, 'transmission control module' code even though we were experiencing the same symptoms. He recommended that we take it to the dealer as they would be able to examine the problem better than he could.
That same day, we reluctantly took it into the dealer with the thought that it might cost more, but maybe they've had a bit more experience with Jeeps and had better equipment. AND maybe they could finally solve the problem. After examining the vehicle, and isolating components, we heard back that we needed yet another shift solenoid pack and a range sensor. We were assured that this was the culprit because that's what the machine came up with. Is it possible that bad parts had been installed both times!?! I found this to be unlikely, but what do I know? I stupidly agreed. The car was returned with smiles and no symptoms. $750 was exchanged and we went on our way.
<24 hours later: limp mode and CEL P0700.
We brought it back in the next day and 3 days later, we were told that there was a definite short in the wiring harness and that it would take 4 days and $2700 to fix. The one thing that I was sure of, was that I needed to leave that place. He gave me no specifics and I did not get the impression that they had isolated a wire in particular that was the culprit. Just that there was a bad wire and the whole thing needed replacing. He didn't charge anything for this trip (but certainly didn't offer to reimburse us for the part that I'm now certain didn't need replacing). I was just glad not to be charged more.
But I have reason to have faith in this newest hypothesis. In several instances, after the CEL and limp mode would start, a stop-start of the engine or battery disconnect and reconnect would get us back up to speed, albeit temporarily. This leads me to believe that there is either a short, or a bad connection.
What do you think? Plausible? What should be my next course of action? I’m desperate and out of ideas. We’re running low on patience and the loaned out car that we are using would need to go back soon. Also, we are a young couple who are already well over a $1000 into this project with no end in sight.
I have scoured this forum as an outside observer for months now and have become a big fan. Any help would be greatly appreciated. Sorry again for the long post.