Stilo Engine Power Loss

I had a similar problem with my Stilo. It turned out to be a faulty main relay, which messed with the ECU (Engine Control Unit - basically the car's computer that controls the engine). When that relay is defective, the ECU doesn't get the right signals and can cause all sorts of problems, including power loss and stored error codes. Did the diagnostic tool give you any specific error codes?

Thanks for the quick reply! Yes, the error code pointed directly to the ECU having some kind of internal fault. You mentioned a relay. Is that something I could check myself, and where exactly would I find the main relay you're talking about? Is it easy to get to, or buried deep?

Okay, an internal ECU fault error code sounds very similar to what I saw. The main relay is usually located in the engine compartment, near the fuse box. It's often labeled, but check your car's manual for the exact location. You can try swapping it with an identical relay if you have one (like from the horn, just for testing purposes!). However, if the error code specifically mentions an internal ECU fault, it might be time to visit a workshop. In my case, diagnosis and relay replacement including VAT was around 120€ to get done.

Thanks a lot for the advice! I'll check the main relay as you suggested, but it sounds like I might be heading to the workshop. I appreciate the help in narrowing down the possible causes and giving me an idea what to look for. It was the main relay! I replaced it and the error disappeared!