[fleetfoot]

Symptoms
Starting back in May, my 2013 e92 has started getting random passenger "door ajar" messages where the dome light turns on and the window drops a quarter inch. I've realized that this only seems to happen (sometimes) right as enter dark areas like parking garages and my low beams turn on. It only happens once every week or two though.

Temporary Fix
I've found the only way to get the door to sense as "closed" is to lock the car and leave it for ~10 minutes. When I come back, then the car is fine for another week or two.

Mods
I haven't made any changes to the car in the past 6+ months. Back in 2022 I did hardware a radar detector to the cigarette lighter fuse slot and replace the xenon bulbs with OEM replacements because the originals were dim. My headlight units (including AEs) are totally stock. I do have an AA ECU flash, but that has been on the car for 5 years, so I highly doubt that's causing the problem.

Detective Work
I've explored multiple potential root causes already:
1) Battery is 3.5 years old and testing healthy (12.1v off and 14v+ driving)
2) My indy shop ran diagnostics and didn't find any error codes
3) I examined the door latch and couldn't find any issues (applied lube for good measure)
4) I turned my radar detector off, but the issue still occurred

The most likely root cause sounds like a bad FRM, but my situation doesn't really align with any of the MANY other threads on here describing FRM issues. My symptom is very specific, and I think there's only one thing that causes it: the headlights turning on automatically. I'm going to try driving with my headlights in the "off" position for a while, and I'm guessing that the problem isn't going to resurface.

Questions:
1) Any other ideas of things I could test?
2) The indy shop said if they replaced the FRM it would be $750 and the coding would wipe my ECU flash. If I do an FRM replacement through a site like ecutesting.com I assume I could keep my ECU flash intact?

[fleetfoot]

Anyone else seen this before, or am I just the unlucky one?

[lordnikon]

Do you have aftermarket AE bulbs?

[fleetfoot]

My headlight units (including AEs) are totally OEM/stock

[fleetfoot]

I’m fairly certain I just found the culprit for my issue: the Anker USB charger I started using a couple days before the wonky headlight/door behavior started.

My hypothesis is that the charger (even when not actively charging) has enough draw or interference with the electrical system that becomes a problem when the headlights start drawing power.

I’ve removed the charger and haven’t been able to replicate my problem after numerous tries.

Anyone have another charger they like?

[codeterrorist]

That looks like it has fast charging, so it explains the higher draw. Maybe go with one that is not a fast charger?

[fleetfoot]

Originally Posted by codeterrorist

That looks like it has fast charging, so it explains the higher draw. Maybe go with one that is not a fast charger?

Good call. I’ll see if I can find an “old school” slow one.

[StradaRedlands]

That's just crazy... I can't get over how sensitive these cars are to electrical supply.

[fleetfoot]

So the door ajar issue came back even after removing the USB charger. Maybe the charger started it, but I don’t know. I ended up replacing the battery, with no change. So Monday I sent my FRM into ECU-Pro. They diagnosed it with a short circuit in the FRM, recoded it, and mailed it back today for $250. Got it back in the car this evening and everything appears to be good now after multiple tests. Hopefully it stays that way this time. What a PITA.

[fleetfoot]

So the door ajar warning came back. I ended up replacing the FRM with a refurb and that finally fixed it. No issues for a month now. It seems the door latch was alright after all.

[Tambohamilton]

My 'fix':
https://www.e90post.com/forums/showp...0&postcount=29