Sentra Start Stop Failure

Whoa, that sounds annoying! I had something similar happen with my old Peugeot. The eco mode just refused to work. Did you check the battery? Mine was totally drained, causing all sorts of weird electrical gremlins.

Could you elaborate on the symptoms your Peugeot exhibited beyond the eco mode malfunction?

Yeah, sure. Besides the eco mode being totally dead, sometimes the car would struggle to start, and the dashboard lights would flicker like crazy. Eventually, it wouldn't start at all! It turned out to be a really bad battery. Honestly, I'd get it checked out by a professional; electrical issues can be a pain to diagnose.

Based on your experience, I consulted a technician. The battery is heavily discharged or defective, as suspected. The repair cost is about 290€.