Jeep Compass Transmission Nightmare, Urgent Help Needed

I had a very similar issue with my 2020 Jeep Renegade Diesel last year. As someone with moderate experience working on cars, I first thought it was related to transmission performance issues, but it turned out to be an undervoltage problem affecting the transmission control unit. The symptoms were nearly identical, erratic shifting, transmission warning lights, and the vehicle getting stuck in limp mode. Initially, the workshop suspected low hydraulic fluid or transmission problems, but their diagnostic tests revealed the electrical system was the root cause. The repair involved: Complete system voltage check, Transmission control unit reset, Testing of all related sensors, Automatic transmission diagnostic scan Total cost was 240 Euro including labor. The transmission started working perfectly after the electrical issue was resolved, with no need for a transmission flush or oil replacement. Before suggesting more specific solutions, could you share: Current mileage on your Compass, When did these symptoms first appear, Have you noticed any other electrical issues (dim lights, slow starter), Are there any other warning lights on the dashboard This information would help determine if youre dealing with a similar electrical problem or if its actually transmission related.

My Compass has exactly 40053 KM on the odometer, and the automatic transmission problems started right after my last regular service. The slipping transmission symptoms you described match my experience perfectly. No electrical issues so far, all lights work fine and the starter is strong. The only warning light is the one for the automatic gearbox. The voltage issue you mentioned is worth checking out, especially since my transmission performance problems came on suddenly. I will ask the mechanic to run those electrical system tests before diving into more expensive transmission repairs. Good to know it might not require a complete transmission overhaul.

Thanks for the additional details about your Compass. Since the transmission problems started right after service, this raises a red flag that differs from my electrical system experience. When service work was done on my Renegade, they sometimes had to disconnect the battery, which triggered my transmission control issues. However, your situation appears different. At 40000 KM, transmission problems are quite unusual for these models unless: Wrong hydraulic fluid was used during service, The transmission fluid level wasnt properly checked, A transmission sensor was disturbed during maintenance Given the timing of your transmission performance issues, I recommend: 1. Having the shop verify the transmission fluid type and level first 2. Request a transmission diagnostic scan 3. Check if any sensors were accidentally disconnected during service My final repair was simple, but yours might be service-related. The good news is that post-service transmission problems are often easily resolved without major repairs. A proper transmission flush with the correct fluid specification might solve your issue, especially if incorrect fluid was used. Would you mind checking your service paperwork to see what transmission work was performed during the last maintenance?

Would you mind checking your service paperwork to see what transmission work was performed during the last maintenance? I just checked my service records and no transmission work was listed, just routine oil change, filters, and brake inspection. This makes the sudden automatic gearbox issues even more puzzling. Looking at my paperwork more closely now, I notice they did disconnect the battery to replace the cabin filter unit. Given what you shared about the slipping transmission problems potentially being linked to battery disconnection, I feel more confident about starting with the electrical diagnostics first. I called the repair shop and scheduled the voltage tests and transmission diagnostic scan for next week. They quoted 180 Euro for full electrical system diagnostics. Will update once I know if its an electrical issue like yours or if the transmission needs more extensive work. Really hoping its just a control unit reset situation rather than major transmission repairs. Thanks for helping me narrow down the potential causes.