hufnik

Hello,

i have Q7 2009 and i recently found out that my tail lights are not as everyone else's and i'll explain.

i just found that my 'working' set of tail lights are the one that located down in the rear bumber rather than the ones located up on the sides of the license plate.

since i found out about this i'm looking at every Q7 and every single one of them has the upper set working and the ones in the bumber disabled.

anyone else notice this thing? any idea how to switch between them? i drove after my wife the other day and noticed that i can bearly see the lights in mid-day, while the upper set is much more clear and easy to see.

Thanks!

Jusforfun

This is the setup for when the tailgate is open! I suspect you have a bad connection or programme fault that is supposed to tell it to revert to normal lights when trunk is closed. There should be a fault code generated for VCDS. Do youget any other warning lights on dash?

Arrie

And I would add that if the wire harness to the switch that controls lights between bumper and main tail lights is not connected the lights stay in the bumper.

Wire harness is right in the middle by the rear hatch lock catch under the back floor, i.e. when you open the floor in the back you should see this wire harness hanging down in the middle. Make sure all wires are in place and harness correctly connected.

Funny enough but it is possible to damage this wire harness if the floor is open and space used for transporting something else that that spare tire. Harness is hanging there in open to be hit with whatever there is.

The comment that tail lights in other Q7s are only at main and not in bumper is strange as I have the small corner light on in the bumper at all times. The difference is that wehen hatch is opened the main tail lights go out and main lights in the bumper come on but the small corner lights in bumper stay on at all times.

Is there something strange going on with my tail lights?


Arrie

AUJ

Resurrection of old post:

My 2007 4.2 is set up the same way. Will follow up on it later. Thanks for the harness suggestion.

AUJ

Tested harness at both tailgate tail-lights with voltmeter, power is present. Unplugging harness when car is running sets off a dash alert of brake light. Plug it back in, no dash warning, but no main tail-light operation, either. Probably software or switch complication. Others with similar issues have your service guy look up JV Recall 55612099 431WA03. Hope this helps others.

mawfth

There's a sensor in the rear tailgate that can get wet and short out-i had the same problem with my 2011 Q7. Simply requires the sensor is replaced - when they check it, it should show that the signal to the upper rear lights in not going through

AUJ

Thanks also. Just got the VCDS codes 02914 (G525) and 02915 (G526) that indicate both tailgate sensors are shorted.

AUJ

Just to build on knowledge base: There will be fault codes 02914 and 02915 as well as 2 lamp codes.

Emergency function
In the event of a fault in switches G525 and G526,
the system switches over from the main rear lights
in the tailgate to the additional rear lights in the
bumper. This action is not indicated in the dash
panel insert.
In this case, a new attempt to switch on the main
rear lights in the tailgate is not made until the next
ignition OFF/ON cycle.


So, no dash warning.

These sensors are actually micro-switches G525 (red,left) and G526 (red, right). There is actually a flap (yellow) that operates the open or closed position of the two micro-switches.


The micro-switches feed the CAN-BUS convenience system central control unit 2 J773 which directs the operations. Am hoping to dig into it soon.

ATL2.8Qmmm

One of the microswitches is wearing out and I'm having an intermittent problem with the tail lights not lighting up. Anybody have the part number? I had it apart yesterday and got it to work a little better by cleaning it and putting a little cardstock wedge to reposition the switch but I probably should swap it out. It looks like you could replace the little microswitch if you could get a part number for that and find a supplier like Mouser or Digikey.

ATL2.8Qmmm

4L0959121