DRL control?
 

Hi gang!


The DRL (daytime running lights) on my 2004 3.0i aren't working and the lamps are ok and work on 'flash to pass'.


Anybody know what controls the lower output level for DRL?


I think that for the US market they're off by default but can be coded 'ON'. My truck is a Canadian model and the DRL used to work OK.


TIA!

Is your light switch set to "auto" lights?

So they used to work but don't anymore?



But the lights work when you turn them on?

DRL doesn't care where the headlight switch is set. They're supposed to work all the time the engine is running.

Correct. HID lows and highs work (bi-xenon), and the inner halogens work for 'flash to pass'.

Sounds like the LCM just isn't activating them for DRL. Do you have access to PA Software/BMW Scanner to check and see what the LCM is coded to do? Seems odd but I don't know what else it could be.

Part my of my post is missing. Cover the sensor with a dark cloth. Does it switch lights?

First step is to verify the coding is still set to DRL on via NCS Expert.

If it is, I would probably next replace the bulbs just to be sure - they may be failing intermittently, perhaps the flash to pass "brightness" is less bright than it was before, and the DRL brightness is so dim that it is not illuminating.

If DRL's are coded on and bulbs are verified to be good - then it is possibly an LCM issue. The LCM controls the DRL's - it just sends a lower voltage to them for DRL operation.

Any possibility of activating DRLs on pre-LCI US-spec with xenons?