F31 Brake light issue
Discussion
LosingGrip said:
Would there be a separate fuse for nearside and offside?
No.You didn't specify if it was front or rear.
Front indicators are driven directly from the Front Electronics module and rears from the Rear Electronics module. There are no fuses between the modules and the actual indicators.
If it was me, I'd be checking for continuity between the relevant lamp holder and the relevant pin on the relevant control module. I can provide wire colours/pin numbers if you provide vehicle model/age etc.
Assuming continuity is good, then it's more than likely a faulty module. If no continuity, you have a broken wire somewhere.
ian332isport said:
No.
You didn't specify if it was front or rear.
Front indicators are driven directly from the Front Electronics module and rears from the Rear Electronics module. There are no fuses between the modules and the actual indicators.
If it was me, I'd be checking for continuity between the relevant lamp holder and the relevant pin on the relevant control module. I can provide wire colours/pin numbers if you provide vehicle model/age etc.
Assuming continuity is good, then it's more than likely a faulty module. If no continuity, you have a broken wire somewhere.
Thanks it's a 2013 F31 320 Touring. You didn't specify if it was front or rear.
Front indicators are driven directly from the Front Electronics module and rears from the Rear Electronics module. There are no fuses between the modules and the actual indicators.
If it was me, I'd be checking for continuity between the relevant lamp holder and the relevant pin on the relevant control module. I can provide wire colours/pin numbers if you provide vehicle model/age etc.
Assuming continuity is good, then it's more than likely a faulty module. If no continuity, you have a broken wire somewhere.
It's the brake not the indicator but assuming the above is still the same?
The bit that confuses me is I can remove the nearside taillight. Plug it in to the offside and it works.
Plug the offside into the nearside which did work and it doesn't work. To me the connection is all good as it works when the other one is plugged in.
So there is something within the taillight that is broken...but having replaced the holder I can't work out wtf it could be?
Huskyman said:
If the light works when plugged into the other side then it isn’t getting power, or a ground is missing. What state is the connector for the light on the affected side? Any signs of corrosion on the pins?
Ah good shout...although the tail light works, would just one effected pin effect the brake light side of things? LosingGrip said:
Thanks it's a 2013 F31 320 Touring.
Thanks.LosingGrip said:
It's the brake not the indicator but assuming the above is still the same?
My bad. I thought I read it was the indicators. Same principal though.Brake lights are driven directly from the Rear Electronics Module (REM). Left brake light should be a black/yellow wire that comes from pin 9 of connector 14B on the REM. For reference, the right brake light is a black/blue wire from pin 21 of connector 12B. You can find the REM on the right hand side of the boot, up above the battery. You'll probably need to remove the side trim to access it though. A174 is the REM. 14B is labelled '1' in the 2nd image below. 12B is labelled '3'. None of the fuses on the REM relate to lighting. They're for rear screen defogger, rear electric windows, rear wiper etc.
Using a test meter or test lamp, you should be able to test if the REM is providing the correct output. You can also test for continuity on the black/yellow wire to make sure the wire is intact.
It's not uncommon for the rear light connectors to melt, so have a good look at the connector before pulling anything else apart.
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