Jeep Compass Power Loss: DEF System Failure Alert

I had a very similar issue with my 2016 Jeep Cherokee diesel last year, and as someone with some hands-on experience maintaining diesel engines, I understand your concern. The symptoms you describe match exactly what I experienced, reduced power, sluggish acceleration, and the check engine light. The car computer indeed limits engine performance as a protective measure when it detects potential issues. In my case, it turned out to be complications from a third-party chip tuning that was previously installed. After running a detailed diagnostic scan, the workshop found that the engine control unit was showing conflicts between the original programming and the aftermarket modifications. The fix involved resetting the engine control module to factory settings and properly recalibrating the system. The total repair cost was 180 Euro, which included diagnostic work and reprogramming. Before suggesting specific solutions, it would be helpful to know: Has your Compass had any performance modifications or chip tuning done? What specific diagnostic codes are showing up? When was the last time you had routine maintenance done? Did this issue start suddenly or develop gradually? This information would help determine if your issue is similar to what I experienced or if it might be something else entirely.

Thanks for the input. Last service was at 156430 KM and the fault code scan actually identified issues with the DPF sensor. The workshop initially suggested a full DPF replacement but after a deeper vehicle diagnostics session they found the sensor wiring was damaged. The repair cost was 320 Euro which included scanning the car computer and replacing the wiring harness. The engine issue was resolved after the fix and power returned to normal. No more reduced power warnings since then. For others with similar symptoms, worth checking sensor connections before assuming major component failure.

Thanks for the update on your Compass repair. Interesting that you had a DPF sensor issue, my Cherokee actually had a similar wiring problem about 6 months before the chip tuning complications I mentioned earlier. The dashboard light and reduced power mode can trigger for various sensor-related faults. Using a quality auto scanner helped identify the specific diagnostic code, saving both time and money by pinpointing the wiring issue rather than replacing the entire DPF unit. 320 Euro seems reasonable for the diagnostic work and wiring harness replacement. My sensor wiring repair was around 290 Euro, so the costs are in line. These sensor faults are more common than many think, the wiring can degrade from engine heat and vibration over time. Good call on sharing this for others experiencing reduced power warnings. A proper scan tool diagnosis should always be the first step before assuming major components need replacement. Often the car computer is just responding to faulty sensor data rather than an actual mechanical problem.

A quick update for those following this thread, after getting the DPF sensor wiring replaced, my Compass is running perfectly again. The diagnostic scan proved crucial since it saved me from an unnecessary full DPF replacement that would have cost much more than the 320 Euro I ended up paying for the wiring fix. The fault codes in the vehicle computer were definitely pointing to the sensor issue. Once the damaged wiring harness was replaced, all the engine power came back and the dashboard light cleared up. Regular driving has been completely normal for several weeks now. For anyone else facing similar reduced engine power symptoms, definitely get a proper scan tool reading before agreeing to major repairs. My experience shows that sensor and wiring issues can mimic more serious problems. What initially seemed like a potential DPF failure turned out to be just damaged wiring, a much simpler and cheaper fix. Really appreciate all the helpful responses on this forum. They helped me better understand the issue and ask the right questions at the workshop.