BP-Hatzer3

A user on MT had the same problem. The contacting lugs did not have connection so the error was not erasable, plz check.

When the leds do not work the comfort-module turned power off so you do not have power on the pins either.

BergeyRPI

I want to add my experience so others don't have to waste their time. My left one was out and after screwing around with it for a while, switching bulbs, checking for voltage, etc., I determined it wasn't making good contact with the two flat copper plates. The two springy sheet metal things were sticking up high enough but they were out of plane. I had to bend the tab on the right down so that it would contact lower when I pressed it in. It's tough to describe but I had to bend the tab away from the bulb, so that it would touch the copper plate better when I reinstalled the housing.

iaflyer

I know it's an old thread, but it helped me. If you measure the voltage across the license plate connectors, and only get 0.5v, it's OK. It's like a "check voltage" to see if there is a bulb there. After you put the bulb in, next engine start it will see the bulb and put the regular voltage to the circuit.

My 2010 A6 license plate bulbs were corroded - after drilling out the screw I replaced the whole bulb assembly with a LED bulb assembly with a 2018 part that worked great. I got the part number from another thread here, but it was 4H0943021 and 4H0943022 (left and right) and they popped in, worked without an problem.

Mikko Korhonen

I too have problems with the number plate lights on C6 Avant 2010. I had swapped the old rusted ones to led ones and they worked fine until there was a break in in the car and the thiefs decided to steal the plate lights as well. (big catch!) Now when the car had been dormant for half a year and I bought new led ones they don´t work at all. Does anyone have an idea what it could be?

The car itself doesn´t give any other error than the normal number plate light- error in console. I don´t have any OBD reader to check it deeper.

There doesn´t seem to be any rust in the cars connecting plates but I am going to try to sand them carefully if that is the case.

I did try to bend the connectors to a different position and did start the car even but no effect there either.

slongtin

I found this thread helpful, because though my plate light sockets were springy when removing and reinstalling, they weren’t working. I was trying to get LEDs in there, and tried both directions. Put regular ones back on and they didn’t work, either. Bent the spring pins back out and viola - paydirt.

So put the LEDs back in, and happened to notice that they came on for a brief second, then went off and gave the bulb out warning. Turned them around, same thing. Put the regulars back, works fine.

Could it be that the LEDs draw too little power for the computer to know they’re there?

FALLENANGEL408

I know this is old thread but maybe this could help others 1 license plate bulb was out went to replace both and got error light message and niether bulb was working, did the sanding both connectors on car and on bulb casing no luck gave up and hour later was thinking I'd try little foil, wrapped little piece around bulb case terminals 2 on each casing popped back in and it worked! Hope this helps others as I was stuck and frustrated

painintheA6

I am having the same issue as you. Both terminals have voltage. One was out, bought two new assemblies with bulbs.
One crumbled on the way out and the other broke. I think my issues its just not hitting the terminal no matter how I manipulate it.
Can you elaborate a bit more on what you did?
Did you wrap the contacts on the assemblies to extend its length to touch the terminal contact plates? My terminals have play in them and its difficult to determine if they are making contact at all.

FALLENANGEL408

correct i wrapped the contacts on the bulb part but not to make longer but to make it thicker to contact other side