Sporadic short duration power loss

[NigeElan]

Hi all, I’ve just started experiencing a new issue with my S2. I was driving up a hill and the engine warning light flickered on and the car lost power for a second. This happened again a few seconds later, but then didn’t reoccur for the rest of that journey. Later in the day I drove it for another 30 miles and she didn’t miss a beat. However, yesterday took her out and the fault kept repeating. As the engine lost power the warning light flicked on, but only for a couple of seconds, if that. One other point to note, when I flashed the headlights, it seemed to set off the engine losing power and the warning light coming on. When I got home, I flashed the lights again while moving slowly and the car stalled!? As I was going slowly the second time, I was able to hear a strange electrical noise, that sounded like it was coming from behind the instrument cluster. I’ve performed the paper clip test and it’s just repeating code 12.... the only thing I’ve changed recently is the fuel, normally on superplus but due to unavailability I used used 95.... but I used to run it on 95 petrol years ago with no issues?

Any suggestions on what to check would be gratefully received

[alan e]

I would start by checking all the Earth connections inc the one at the back of the engine.

[Simon_P]

As Alan says check the earth connectons.

While you are checking the battery connection disconnect one lead to reset the ECU and rule that out.

I can't remember the wiring but it would also be worth giving the ignition switch a wiggle in case there is a poor connection.

I recently had a similar issue with my Volvo - I cleaned every fuse which has improved it.

[NigeElan]

Thanks for the comments, I’ll check these suggestions out.

[NigeElan]

I think this is now sorted. For info, looks like it was a loose connection to the battery....