Why did I lose power?

dikidera · Post by **dikidera** » 20 May 2025, 14:04

I was just driving on a empty country road and it was already night, and just Iike in those alien abduction movies, my car lost all electrical power, for a second, the entire car blacked out for a second and then power came back, though i had to stop and crank the car anew.

Before that, seconds before, the only precursor was that my headlights started to flicker.

This smells like CEM, or battery? S60 2005 face-lift, L-shaped CEM. Every once in a while I would hear a relay click behind the dashboard but no symptoms.

Post by **jonesg** » 20 May 2025, 14:55

Did the headlights go out?
if yes, then I say battery/circuit, if it was ignition i'd expect the lights would stay on.

dikidera · Post by **dikidera** » 20 May 2025, 15:52

I mean the entire car, the instrument cluster, headlights, radio, all power. Even the door modules as I heard them resetting,

Post by **vtl** » 22 May 2025, 05:26

CEM relays. In your model year they are soldered. Start with EWD, try to identify which relay are responsible for powering modules that went out.

You may also have a water damage in CEM.

dikidera · Post by **dikidera** » 25 May 2025, 09:05

Now that you mention water damage, I did have a water leak from the sunroof drains being clogged that moved towards the A pillar on the driver side, dripping around on the air vents. Twice. It may have just needed time to develop symptoms...maybe.