Wagoneer Trans Failure: Check Engine + No-Start Issues

Having dealt with similar transmission failure symptoms on my 2018 Jeep Grand Cherokee with the gas engine, I can relate to your situation. The symptoms you describe match what I experienced, transmission sensor issues that affected both starting and shifting performance. The main problem was a faulty shift lock solenoid combined with a deteriorating transmission control unit. These components work together to manage the neutral position and gear engagement. When they malfunction, the transmission cannot properly determine gear positions, leading to the slipping sensation and starting issues you mentioned. The repair required: Replacing the transmission control module, Installing a new shift lock solenoid, Reprogramming the new components, Full transmission diagnostic scan This was a serious repair that required specialized diagnostic equipment. The transmission had to be partially disassembled to access the failed components. The check engine light was triggered by multiple transmission sensor readings being out of acceptable range. The good news is that catching these symptoms early helps prevent complete transmission failure. Based on your mileage and symptoms, it sounds very similar to what I dealt with. Would recommend having the shop specifically check the shift lock system and transmission control unit.

Thanks for the detailed breakdown of your transmission repair experience. Did the fix end up solving all the transmission issues completely? And would you mind sharing what the total repair cost was? Just dealing with similar symptoms in my 2021 Wagoneer and trying to budget for potential repairs. Also wondering if you had any other automatic transmission problems pop up since the repair was done?

The repair completely resolved all the transmission issues. The faulty control unit was causing the transmission failure symptoms, but once replaced, the car worked perfectly again. The shift lock system and neutral position functions are now operating as they should. The total repair came to 1000 Euro for fixing the affected control unit. While it was a significant cost, it was worth it to prevent more extensive transmission damage that could have resulted from delaying the repair. Since having the transmission sensor and control unit replaced, there have been zero transmission-related problems. The automatic transmission shifts smoothly, engages park brake properly, and the check engine light has stayed off. Regular maintenance has kept everything running well for the past few months. Acting quickly when these symptoms appeared helped avoid more costly repairs. Transmission issues tend to compound when left unaddressed.

Thanks everyone for the input. I took the car to my mechanic last week after reading the responses here. Turns out my automatic transmission problems were indeed related to the control module, just as suggested. The gear shifter would sometimes get stuck and the transmission sensor readings were all over the place. The mechanic found multiple error codes pointing to a failing control unit. The repair took about 6 hours total and cost 1200 Euro. The shop replaced the transmission control module and recalibrated all the sensors. They also performed a full diagnostic scan to ensure everything was communicating properly. Been driving for a week now and the transmission issues are completely resolved. No more check engine light, smooth gear changes, and the car starts perfectly every time. Really glad I caught this early before any major transmission failure occurred.