Assistance Needed for Programming BCM for LED Fog Lights on VW Golf MK7 (2014 TDI to

[DV52]

I'm guessing you are implying this will have to be a firmware update, replacement, or resistors ?

No to "firmware update"! As I've said a number of times in this thread, the fact that a 12V signal appears at the fog-light connectors (with the fog-light lamps connected) when the fog-light switch is activated means that the BCM is properly operating the fog-light function. My understanding from your responses is that this happens. So more coding and/or firmware updates won't (shouldn't) change this BCM outcome.

In requesting the BCM admap, I was hopeful that I could spot another reason for this problem. But despite the mighty strange admap that you have provided - none of the weirdness dispels the fact that the BCM is operating the fog-light function correctly at the connectors.

So I'm not sure how familiar you are with electrical theory - but this situation seems to be one where the BCM is supplying the correct voltage, but no electrical current is flowing out of the BCM. If I was looking at this problem anew, I would suspect that the fault was due to incorrectly polarized LEDs. As I assume you already know, LED is short for Light-Emitting-Diode and diodes conduct ONLY if the +ve voltage is connected to the anode lead. If the +ve voltage is instead connected to the diode's cathode lead, the LED won't conduct resulting in "no electrical current flowing"

But, I assume that when you hook-up the temporary battery supply to confirm that the fog-light lamps actually work. you connect the +ve/-ve battery leads to the connector pins with the same pin polarity as the the way that the BCM supplies power.

So, because we have ruled-out coding and reverse-polarity as possible causes for this problem and because you have assured me that the LEDs work properly - I'm scratching my head!!

Don

[ak77]

No to "firmware update"! As I've said a number of times in this thread, the fact that a 12V signal appears at the fog-light connectors (with the fog-light lamps connected) when the fog-light switch is activated means that the BCM is properly operating the fog-light function. My understanding from your responses is that this happens. So more coding and/or firmware updates won't (shouldn't) change this BCM outcome.

In requesting the BCM admap, I was hopeful that I could spot another reason for this problem. But despite the mighty strange admap that you have provided - none of the weirdness dispels the fact that the BCM is operating the fog-light function correctly at the connectors.

So I'm not sure how familiar you are with electrical theory - but this situation seems to be one where the BCM is supplying the correct voltage, but no electrical current is flowing out of the BCM. If I was looking at this problem anew, I would suspect that the fault was due to incorrectly polarized LEDs. As I assume you already know, LED is short for Light-Emitting-Diode and diodes conduct ONLY if the +ve voltage is connected to the anode lead. If the +ve voltage is instead connected to the diode's cathode lead, the LED won't conduct resulting in "no electrical current flowing"

But, I assume that when you hook-up the temporary battery supply to confirm that the fog-light lamps actually work. you connect the +ve/-ve battery leads to the connector pins with the same pin polarity as the the way that the BCM supplies power.

So, because we have ruled-out coding and reverse-polarity as possible causes for this problem and because you have assured me that the LEDs work properly - I'm scratching my head!!

Don

Yes mate above all tried and tested. I really wanted to have the LED lights at fault here but they function isolated outside the BCM. The only other thing I haven't tried is tricking the BCM the I'm still running the halogens by adding resistors.

But honestly mate , you ben excellent and learnt heaps Cheers.
I'm at the give up stage , or so close to it