BCM Coding: Turning on Fog Lights Activates Small Bulbs in Headlights

[MunsterScot]

Hi All,
New to this forum and have an issue with my 2011 VW CC 2.0 TDi 170BHP DSG I'm hoping you can help with.

I've had the car for 7 years now with no complaints. It's up to approx. 250k miles.

Approx. 18 months ago I had to bet the BCM changed. The garage that did it (VW Indy) got everything done with the exception of one coding problem. When the front fog light switch is turned on instead of the fog lights coming on there are small bulbs in the headlights (not the side light bulbs/parking light bulbs) that shine side ways (to the outside of the car) that come on instead (like they would be turning lights). These bulbs never came on before the BCM was changed. In fact I didn't even know they were there.

At the time the VW Indy couldn't get the coding to work. I didn't worry about it back then as car was working.

The car has now failed its annual car test (NCT in Ireland. Like the MOT in the UK) for the fog lights not working so I need to get them fixed.

I have VCDS. I've had a look at the coding of module 09 but nothing jumps out at me. When I use VCDS to drive the fog light output the small bulbs in the headlights I mention above come on. Hence why I think it is a BCM coding issue.

Any idea what coding change may be needed that I can try. Other than that I'll have to take it to an Auto Electrician / coding garage.

Thanks in advance.

[Crasher]

That is odd and failing the NCT over it also odd, I don’t think it would fail the MOT for front fogs, I will check. I would use ODIS for the coding but if you have genuine VCDS, you can join the Ross Tech forum and get accredited, then people like Sebastian should be able to work the coding value out for you. I would have thought copying and pasting the old value would have worked but I have had some nasty experiences doing that on your cars platform when fitting a new BCM.

[MunsterScot]

Thanks Crasher.

For the NCT if front fog lights are fitted they must be working to pass the NCT (from memory the MOT is the same).

I was looking into if I could just remove the front fog lights for the re-test. Working on - if they are not fitted they don't have to work. But the Irish Road Safety Authority (RSA) says your not allowed to do that. As front fog light were originally fitted to the car removing them could be seen as making the car less safe. Which isn't allowed.

When the Indy garage fitted the new BCM they copied the coding over from the old faulty BCM to the new one but the fog lights wouldn't work. The turning lights in the head lights would always turn on when turning the fog lights on.

I've done a bit of a wiring mod / bodge this morning to get the fog lights working. I've disconnected the wiring plug to the fog lights and taped them up. I've unplugged the connecter to the turning light bulb in the head light but left the bulb in place. I've then put wire from the turning light plug to the bulb of the fog lights. Fog lights now working and no error message / warning coming up in the dash. It will do for now to get it through the NCT retest. Then if coding can be fixed I can do that later.