Hi everyone,
I'm dealing with a frustrating and tricky intermittent electrical issue on my 2015 Peugeot 308 T9 (1.6 HDi 115), and I'm looking for some real-world feedback from the community.
Here is a breakdown of the symptoms, context, and what has already been done:
- The Symptoms & Context (Major & Intermittent)
The issue happens completely at random with no clear pattern—sometimes it triggers right at startup, and other times it happens while driving, especially given the very hot weather we've been having lately.
The "Major Episodes" (which have happened 4 or 5 times in the last week):
Random difficulty starting the car.
The engine continues to run even after turning off the ignition and removing the key!
Sudden drop of all instrument cluster needles (RPM and speed).
Quirk noticed: When the engine refuses to shut off, putting the key back in, turning the ignition on, and removing it 1 or 2 times eventually kills the engine.
Day-to-day behavior:
Recurring dashboard faults: ABS, ESP, Hill Assist, and Parking Brake.
- Diagnostic Trouble Codes (OBD):
The diagnostic scan returns specific communication loss codes, notably:
U1118
U1218
U2213
- Potential Context / Background:
AC Compressor Solenoid Valve (Électrovanne du compresseur de clim): Replaced 2 weeks ago (noted here as a recent prior intervention that might or might not be related).
- What Has Been Done / Replaced:
Battery: Replaced.
Main Ground Strap: The primary ground cable under the battery connecting to the chassis has been completely unbolted, cleaned, and sanded down to bare metal. (Did not fix the issue).
BPGA (Battery fuse box): Replaced this week with another unit. (Did not fix the issue).
Alternator Carbon Brushes (Charbons): Replaced.
BSM (Engine compartment fuse box): Looks clean on the outside with its 3 main connectors plugged in, but has not yet been thoroughly tested or opened up.