‘Light Out’ warning on after tailgate conversion.

Littleblackflash

Littleblackflash

Auto Engineer
VCDS User
VIP Member
T6 Guru
I've converted my barn doors to a tailgate with LED lights. But I have a orange warning for bulb out on the instruments.

VCDS scan showed no fault codes.

If I go into 17-Instruments and go into measured values, what should I be looking for? The only concern I've found is "Status on input signals 4-Driving light Malfunction" = Active.

Any ideas what causes this?
 
I'm sure bulb monitoring should not be active for the LED rear clusters.

If you've changed from standard to LED clusters I think you need to disable the rear bulb monitoring function.

Not sure what VCDS setting as I've not done it. . . . . . Is there not an option for rear LED clusters in the reprogramming?

I'll have a look tomorrow.
 
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​
 
Last edited:
Thanks. So I think I'll try Byte 19 Bit 6 Lamp Diagnostics for tail lights - make it inactive.

I'll try tomorrow.
 
No luck :(

Status on input signals 4-Driving light Malfunction = Active. This is the problem still. When I have the lights switched off, this warming is not active, but as soon as the lights go on Auto or On, the warning becomes Active.

Central Electronics Control Unit Byte 19 Bit 6 - Lamp Diagnostics for Tail Lights = This is not active. I've tried changing the coding to 1000 1001 but I still get the warning.

I've checked several times, I don't have any bulbs out.

Any other ideas on what to try? I brought the lights through the for sale section on here so I'm wondering if they are not genuine OE. I'll try the old lights this weekend and see if that solves it.
 
Last edited:
If you could post a copy from VCDS autoscan as below so we could have a closer look at the codings. These are from two different vans, both having tailgate and LEDs.

MY16
Address 09: Cent. Elect. (J519) Labels:. 7E0-937-BCM-V1.clb
Part No SW: 7E0 937 090 HW: 7E0 937 090
Component: BCM PQ25 Max4 H80 0736
Revision: B9080001 Serial number: 0771 316150034
Coding: 62F8793A0A21209301284F602DEB87F4C0B47389E04579C03204003F0860

MY18
Address 09: Cent. Elect. (J519) Labels:. 7E0-937-BCM-V1.clb
Part No SW: 7E0 937 090 C HW: 7E0 937 090 C
Component: BCM PQ25 Max4 H82 0752
Revision: B9082001 Serial number: 4000 049181011
Coding: A0A8393A0A61341393284F402DEB87F4C0947389604579C03304003F0860
 
65Plate PV

Address 09: Cent. Elect. (J519) Labels:. 7E0-937-BCM-V1.clb
Part No SW: 7E0 937 090 HW: 7E0 937 090
Component: BCM PQ25 Max4 H80 0733
Revision: B9080001 Serial number: 0771 269151942
Coding: A0A4303A0A6134B193284F746CEB8E748FA0708F60CC6D60320400220800

Thanks
 
Littleblackflash said:
Any other ideas on what to try? I brought the lights through the for sale section on here so I'm wondering if they are not genuine OE. I'll try the old lights this weekend and see if that solves it.
Click to expand...

I’m in the same boat, with genuine lamps, so I wouldn’t waste your time swapping them out (I don’t even think there are any aftermarket tail lamps that mimic the OEM lamps - the aftermarket ones look different).
 
They look like OE lights and have an OE quality about them so I assume they are. So it must just be a coding error.
 
@Littleblackflash do you still have your old barn-doors? If so (and I can’t recall how the lights come out, if at all) try disconnecting your LED numberplate lights and connecting the original halogen lights to see if it’s those causing the error.

The connectors are probably different so you may have to Blue Peter it :thumbsdown:
 
I’m not 100% sure but I think all tailgates come with LED numberplate lights and barn doors come with standard lamps so ads could be onto something there ??
 
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There are obviously quite a few differences in the coding. Picked below those that seem to be related.

May be far fetched but byte 18 is the light setup - which is now different in the modified van, and also in the coding- would be my best/only guess. Possibly then another try on byte 19.

Byte#
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
62 F8 79 3A 0A 21 20 93 01 28 4F 60 2D EB 87 F4 C0 B4 73 89 E0 45 79 C0 32 04 00 3F 08 60 MY16 Panel Van OEM LEDs tailgate
A0 A8 39 3A 0A 61 34 13 93 28 4F 40 2D EB 87 F4 C0 94 73 89 60 45 79 C0 33 04 00 3F 08 60 MY18 Panel Van OEM LEDs tailgate
A0 A4 30 3A 0A 61 34 B1 93 28 4F 74 6C EB 8E 74 8F A0 70 8F 60 CC 6D 60 32 04 00 22 08 00 65Plate PV


Byte 18 is light setup, the OEM configuration has bits 0-1 set unlike the now modified van.


Bit
7654 3210
---- ----
0111 0011 OEM MY16 Panel Van
0111 0011 OEM MY18 Panel Van
0111 0000 65Plate PV

Byte 18 Bit 0~7 00 Light Setup: Standard/Parameter Settings (EEPROM)
Byte 18 Bit 0-1 01 Model parking light: 5W + 5W (Ausführung Standlicht: 5W+5W)
Byte 18 Bit 3-4 00 Indicator lights: 21W/21W/5W (Ausführung Blinkleuchten: 21W/21W/5W)
Byte 18 Bit 5 Output high beam active (Ausgang Fernlicht aktiv)
Byte 18 Bit 6-7 40 Brake lights: 21W/21W/5W (Ausführung Bremsleuchten: 21W/21W/5W)


Byte 19 is lamp diagnostics stuff. The proposed bit 6 to turn off tail light monitoring was already the same as OEM. Also setting the byte the same as OEM "89" seemed to rule out the difference in control method (bits 1,2). May be worth another try after modifying byte 18?

Bit
7654 3210
---- ----
1000 1001 OEM MY16
1000 1001 OEM MY18
1000 1111 65Plate PV

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


Byte 27 - mostly undocumented.

Bit
7654 3210
---- ----
0011 1111
0011 1111
0010 0010

Byte 27 Bit 0 License plate light in LED design (Kennzeichenbeleuchtung in LED Ausführung)
Byte 27 Bit 1 Activation terminal 58d active via Body Control Module (BCM) with pulse width modulation (PWM) (Ansteuerung Klemme 58d über Body Control Module (BCM) mit Pulsweitenmodulation (PWM) aktiv)


- - - - - - - - - - - - - - - -- - - - - - - -
Byte 11 has some more lamp diagnostics stuff but nothing obvious.

Bit
7654 3210
---- ----
0110 0000 OEM MY16
0100 0000 OEM MY18
0111 0100 65Plate PV

Byte 11 Bit 0 High beam via shutter (xenon) active/installed (Fernlicht über Shutter (Xenon) aktiv/verbaut)
Byte 11 Bit 1 Lamp failure detection for additional position lights active (Lampenausfallerkennung für zusätzliche Positionsleuchten aktiv)
Byte 11 Bit 2 Activation of additional position lights via pulse width modulation (PWM) active (Ansteuerung zusätzliche Positionsleuchten über Pulsweitenmodulation (PWM) aktiv)
Byte 11 Bit 3 Additional position lights installed (Zusätzliche Positionsleuchten verbaut)
Byte 11 Bit 4 Activation of Back-Up Light via pulse width modulation (PWM) active (Ansteuerung Rückfahrleuchte über Pulsweitenmodulation (PWM) aktiv)
Byte 11 Bit 5 Activation of license plate light via pulse width modulation (PWM) active (Ansteuerung Kennzeichenbeleuchtung über Pulsweitenmodulation (PWM) aktiv)
Byte 11 Bit 6 Lamp Diagnostics for Back-Up Light active
Byte 11 Bit 7 Lamp Diagnostics for License Plate Light active


Byte 16 - more lamp diagnostics.

Bit
7654 3210
---- ----
1100 0000 OEM MY16
1100 0000 OEM MY18
1000 1111 65Plate PV

Byte 16 Bit 0 Activation low beam via pulse width modulation (PWM) active (Ansteuerung Abblendlicht über Pulsweitenmodulation (PWM) aktiv)
Byte 16 Bit 1 Activation of fog light via pulse width modulation (PWM) active (Ansteuerung Nebelschlusslicht über Pulsweitenmodulation (PWM) aktiv)
Byte 16 Bit 2 Activation of Daytime running lights via pulse width modulation (PWM) active (Ansteuerung Tagfahrlicht über Pulsweitenmodulation (PWM) aktiv)
Byte 16 Bit 3 Activation of High Beam via pulse width modulation (PWM) active (Ansteuerung Fernlicht über Pulsweitenmodulation (PWM) aktiv)
Byte 16 Bit 4 Lamp Diagnostics for Low Beam active
Byte 16 Bit 5 Lamp Diagnostics for Rear Fog Light(s) active
Byte 16 Bit 6 Lamp Diagnostics for (Separate) Daytime Running Lights (DRL) active
Byte 16 Bit 7 Lamp Diagnostics for High Beam active
 
Thanks for taking the time to write all of the above. Tomorrow afternoon I'll try byte18 first. I've tried all combinations of byte19 and it doesn't solve my issue.

Byte 27 could be worth trying.

I'll let you know how I get on.
 
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mmi said:
..Byte 27 - mostly undocumented.

Bit
7654 3210
---- ----
0011 1111
0011 1111
0010 0010

Byte 27 Bit 0 License plate light in LED design (Kennzeichenbeleuchtung in LED Ausführung)
Byte 27 Bit 1 Activation terminal 58d active via Body Control Module (BCM) with pulse width modulation (PWM) (Ansteuerung Klemme 58d über Body Control Module (BCM) mit Pulsweitenmodulation (PWM) aktiv) ..
Click to expand...

Littleblackflash said:
Winner !!!

Byte 27 - fixed the problem.
I've changed the coding t0 0011 1111 and the warning light has gone.

Many thanks for everyones help.
Click to expand...

Is this byte 27 the relevant monitoring section for rear halogen / LED number plate lights, then?

Does this mean @Littleblackflash will still get an error light if the LED was to fail?
 
I think it was the only change.

I was unable to change byte 18 because the drop down box didn't contain option 73

Byte 11 only have me the option to change bit 6 & 7
Byte 11 Bit 6 Lamp Diagnostics for Back-Up Light active
Byte 11 Bit 7 Lamp Diagnostics for License Plate Light active
I've re-activated them without an error.

Byte 16- I can't remember if I've re-activated any of these warning yet. I'll check.

Adam - No idea. I'll pull the wire off my number plate light tomorrow and see if I get a warning.
 
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