‘Light Out’ warning on after tailgate conversion.

[Ads_Essex]

@Peec i may have found a solution to our coding conundrum on this here thread.

 

[Pexi56]

Hi! I've changed also those taillights to LED-ones; my VW is Caravelle (2016) with barn doors. First there was same bulp-error light as Littleblackflash had.
I've OBDeleven diagnostic failcode reader. No errors found while errorlight was burning!! i changed that Byte 27 Bit 0 ; and no warning light exist anymore!!
Fine; but I have an other issue; those LED-lightclusters are from Vanstyle, and now there's no ACC working !! It just tells me, that front assistant isn't available!! I tried old light clusters back in business, and everything is OK!! Now, what I should change; and what codes effect that issue?

 

[Dellmassive]

have you looked here: Light Warning On

*************************************************************************************
VCDS codes list

I would try first Central Electronics Control Unit Byte 19 Bit 6 - Lamp Diagnostics for Tail Lights active.

EDIT: Worth to check the other bits too. I have LEDs +tailgate, the byte 19 in mine has code 89 = 1000 1001 (bit 7 on the left, bit 0 on the right).

EDIT2:
Byte 19 Bit 0 Control of fog/cornering light via pulse width modulation (PWM) active (Ansteuerung Nebel-/Abbiegelicht über Pulsweitenmodulation (PWM) aktiv)
Byte 19 Bit 1 Control of rear lights via pulse width modulation (PWM) active (Ansteuerung Begrenzung-/Schlusslicht über Pulsweitenmodulation (PWM) aktiv)
Byte 19 Bit 2 Control of brake lights via pulse width modulation (PWM) active (Ansteuerung Bremsleuchten über Pulsweitenmodulation (PWM) aktiv)
Byte 19 Bit 3 Control of indicator/turn lights via pulse width modulation (PWM) active (Ansteuerung Blinkleuchten über Pulsweitenmodulation (PWM) aktiv)
Byte 19 Bit 4 Lamp Diagnostics for Turn Lights active
Byte 19 Bit 5 Lamp Diagnostics for Fog Lights and/or Cornering/Turn Lights active
Byte 19 Bit 6 Lamp Diagnostics for Tail Lights active
Byte 19 Bit 7 Lamp Diagnostics for Brake Lights active
**************************************************************************************

 

[Pexi56]

Ok, I'll try that asap...

 

[mmi]

I have LEDs +tailgate, the byte 19 in mine has code 89 = 1000 1001

WHAT??? You have you changed your van??? The byte 19 is changed! ---> Dodgy Demister

 

[Dellmassive]

WHAT??? You have you changed your van??? The byte 19 is changed! ---> Dodgy Demister

No sorry, my fault - that was a quote from previous thread.....

Above post edited

 

[Pexi56]

No problem!!! That happens every day; especially to me!!!

But my problem didn't get solved; that front assistant still not available. I changed that 19 Bit 6 ; now it's active. That ACC informed on error: Databus error value received. Fault code shows: U112300. No fault lights illuminated...

 

[mmi]

No sorry, my fault - that was a quote from previous thread.....

Above post edited

What a relief . Actually just got scanned a few new/different T6s so was comparing those - factory codings of front/rear LED's. One in the comparison was your "old" one so this "new" just stuck out.

It seems that VW made also some other coding changes related to the LEDs (not seen documented), namely byte 27 bits 2-4 are set to "1" on all van having T6 LEDs also in the rear. In the vans with regular bulbs (barn door) those bits are "0".

Also seems to be byte 18 is "73" with full LEDs (tailgate) and "72" with front LEDs only (barn door).

I'm not sure if the changes are relevant. Anyways, will put out a more refined post later...

EDIT: the update ---> T6 LED headlight retrofit

 

[mmi]

I changed that 19 Bit 6 ; now it's active. That ACC informed on error: Databus error value received. Fault code shows: U112300.

Hmmm... are you saying changing BCM byte 19 bit 6 caused the ACC error? That would be really strange?
Can you communicate with all the other modules?

 

[Pexi56]

Sorry, no.... that error was also before I changed that code; It started immediately after I installed those light clusters.... Yes I can communicate all those.... I hope!

 

[mmi]

Ok... makes sense now..better. Can't see how these BCM codings would affect the ACC.

Strange, almost the new lightclusters are messing with CAN bus traffic? It is only the rear cluster you swapped?
Can you disconnect the feeding lead or fuse so that the clusters are "on line" but not "energized" to see if that makes difference.

 

[Pexi56]

Hi frends! I was away a while and now back in action with this issue. So, I have been discussed with suplier via email, and they are guite suprised with this dilemma. They suggested me, that there's something to do with tow bar electrics and I tried to test this without power in tow bar. Fuses out, but no differens according to ACC!!! Just new databus error; exact same as in the beginning! Now I am helpless with this. Is this something to do with LHD versus RHD model; or is Transporter different from Caravelle (I have)? Of course options make something! I discovered one thing while testing these possibilites; when engine was running and I pressed brakepedal (brake lights on), then I tried to get ACC on; and IT DID!!! But when I released brake (lights off), once again ACC off (Front Assistant not available)!!!! Something to do with brake lights ( or their controll/activation)??? Some byte/bit not right position? I dont't know which!!

 

[Robert]

Did you check and test your brake light switch?
There are 2 separate switches(sets of contacts) within one unit. As far as I remember one is N/O and the other one is N/C.
One is kind of direct feed for brake lights and the second one is confirmation for BCM.