HID Light Issue

[Mistermorgan]

Hey all,

It’s been a little while since I had an issue but I’m glad to be back - have a weird issue with my headlights. The RHS HID headlight isn’t working and have no idea why, so far I’ve tried

- replacing the ballast, igniter and bulb - no dice
- swapped the entire RHS and LHS headlight units over both units work fine on the LHS, neither work on the right
- tired a spare headlight unit I had on the RHS it doesn’t work but works on the LHS
- checked voltage at each pin on the light connector (vehicle side obviously) and voltage is the same on LHS and RHS at every pin with the headlights turned on

From this I’m a little stumped, if the issue was with fuses or LCM surely I would see a voltage variance at the pins from LHS (working) and RHS (not working)

At ignition off I get “check park light” error and when I put the headlights on it automatically turns on front fog lights but I think this it normal behaviour when a light is out right?

Any suggestions would be much appreciated!

Cheers

[crystalworks]

The LCM does some weird things when you have a malfunction. When I had a problem with my AHL module shorting (water intrusion) on my LHS headlight (US car, so LHD), the LCM would disable that headlight low beam. At the time I was unable to troubleshoot it properly as I did not have ISTA/INPA/etc.

I did the same troubleshooting you did with the same result. So I ended up using a jumper wire (with relay and constant +12v) from the LCM that would power the working side so it would also power the non-working side. Drove around like that (non-functioning AHL but working low beams) for 2 years even though I replaced the failed AHL module shortly after. The AHL would not function properly until I finally got INPA running and did a calibration (I think that was the term in the software) of the AHL system. That initialized the replaced AHL module and now all works as it should.

Inspect your modules under the headlight for water intrusion, they are cheaply replaced with good used units. If both your units look good then maybe it's a case of needing to use the BMW software to re-calibrate or re-initialize them?

Sorry for the longish post. Here is a link to the workaround I posted.

https://xoutpost.com/bmw-sav-forums/...questions.html

[Mistermorgan]

Wow thanks so much for this reply, it actually makes a tonne of sense.

I guess what I failed to mention is that I have swapped out the headlight units for new ones which no longer have AHL so this is looking like a symptom of that. I’ll bust out INPA this afternoon and take a look, I’m assuming I would need to code the AHL out of the VO to fix though right?

[Purplefade]

Am I crazy or does the LCM keep an error count and lock "that" light out after "X" number of "failure" detections? I really want to say that I read clearing the error count can fix this issue. Like maybe the ballast was failing and that light failed to light that "X number of times so the LCM locked it out to prevent further damage.


- I could be bat crap crazy too...

[andrewwynn]

That is a normal MO for a few different systems but it should try to light after clearing codes with BMW friendly scanner

[Mistermorgan]

Yeah I thought so too but have cleared codes with foxwell and inpa and no dice.

I have removed the ALC module and coded out not both headlights work fine but I still can’t clear the “check park lights” error which comes up on every start even though the both lights are now working fine

[Mistermorgan]

Yeah I thought so too but have cleared codes with foxwell and inpa and no dice.

I have removed the ALC module and coded out not both headlights work fine but I still can’t clear the “check park lights” error which comes up on every start even though the both lights are now working fine

[wpoll]

"Check Park Lights" is the "angel eyes" or halo lights - I had one blow yesterday and saw this same messgae.