diebeste

Hi!
I have a weird brake light problem - whenever I am braking while using the turn signals, the brake light corresponding to that turn signal is not working. For instance, brake, all three lights working. Indicate left, and left brake light goes out while the amber turn signal blinks (the turn signal blinks, but the light remains off the whole time). Same situation for right signal, and using the hazard lights switches off both brake lights. I have confirmed this using VAG COM - logging the output gives something like this:
Brake switch, turn signal, brake lights
(no turn)
111,00,111
111,00,111
111,00,111
(left turn)
111,10,011
111,00,011
111,10,011
(right turn)
111,01,110
111,00,110
111,01,110
(hazards)
111,11,010
111,00,010
111,11,010

Any ideas?

PaulW

Would have to look at the wiring diagram and find the ground positions. It is using the brake light as a ground path from the turn signal ground because the one it is suppose to go through is bad.

diebeste

Thanks, I'll have a look. Would this happen on both sides as consistently as it does now though?

diebeste

Sorry, I am a real novice at this, so correct me if I am wrong, but for a bad ground I would expect the brake light to go out only whilst the indicator light is actually on, not during the whole on/off cycle (i.e. the brake light does not pulse in opposition to the turn light; it is plain not switched on irrespective of whether the turn light is on or off, as long as the indicator stalk is still in the turn position (or the hazard switch is on) it is off).

MP4.2+6.0

Just confirming, this is a D3 right? And no special wiring, like trailer hitch?

diebeste

I am attaching the dump from VAG COM showing the problem
Thursday,11,September,2008,18:12:42
4E0 910 289 A,,Komfortgeraet H04 0040,

,Group A:,'011,,,,Group B:,'012,,,,Group C:, Not Running
,,Backup Lights,Turn Signals,Rear Fog Lights,Tail Lights,,Brake Test Switch,Brake ECD,Brake Lights,,,,,,
,TIME,,,,,TIME,,,,,TIME,,,,
Marker,STAMP,,,,,STAMP,,,,,STAMP,,,,
,0.06, 00, 00, 00, 11,0.16, 111, 00, 111,N/A,,,,,
,0.26, 00, 00, 00, 11,0.39, 111, 00, 111,N/A,,,,,
,0.50, 00, 00, 00, 11,0.60, 111, 00, 111,N/A,,,,,
,0.70, 00, 00, 00, 11,0.80, 111, 00, 111,N/A,,,,,
,0.95, 00, 00, 00, 11,1.05, 111, 00, 111,N/A,,,,,
,1.15, 00, 00, 00, 11,1.24, 111, 00, 111,N/A,,,,,
,1.34, 00, 00, 00, 11,1.48, 111, 00, 111,N/A,,,,,
,1.59, 00, 00, 00, 11,1.69, 111, 00, 111,N/A,,,,,
,1.79, 00, 00, 00, 11,1.89, 111, 00, 111,N/A,,,,,
,2.04, 00, 11, 00, 11,2.14, 111, 00, 010,N/A,,,,,
,2.24, 00, 11, 00, 11,2.33, 111, 00, 010,N/A,,,,,
,2.43, 00, 00, 00, 11,2.58, 111, 00, 010,N/A,,,,,
,2.68, 00, 00, 00, 11,2.78, 111, 00, 010,N/A,,,,,
,2.88, 00, 11, 00, 11,2.97, 111, 00, 010,N/A,,,,,
,3.12, 00, 11, 00, 11,3.22, 111, 00, 010,N/A,,,,,
,3.32, 00, 00, 00, 11,3.42, 111, 00, 010,N/A,,,,,
,3.52, 00, 11, 00, 11,3.67, 111, 00, 010,N/A,,,,,
,3.77, 00, 11, 00, 11,3.86, 111, 00, 010,N/A,,,,,
,3.96, 00, 00, 00, 11,4.06, 111, 00, 010,N/A,,,,,
,4.21, 00, 11, 00, 11,4.31, 111, 00, 010,N/A,,,,,
,4.41, 00, 11, 00, 11,4.51, 111, 00, 010,N/A,,,,,
,4.61, 00, 00, 00, 11,4.74, 111, 00, 010,N/A,,,,,
,4.85, 00, 00, 00, 11,4.95, 111, 00, 010,N/A,,,,,
,5.05, 00, 11, 00, 11,5.13, 111, 00, 010,N/A,,,,,
,5.28, 00, 11, 00, 11,5.37, 111, 00, 010,N/A,,,,,
,5.47, 00, 00, 00, 11,5.56, 111, 00, 010,N/A,,,,,
,5.66, 00, 11, 00, 11,5.80, 111, 00, 010,N/A,,,,,
,5.91, 00, 11, 00, 11,6.01, 111, 00, 010,N/A,,,,,
,6.11, 00, 00, 00, 11,6.20, 111, 00, 010,N/A,,,,,
,6.34, 00, 11, 00, 11,6.43, 111, 00, 010,N/A,,,,,
,6.53, 00, 11, 00, 11,6.62, 111, 00, 010,N/A,,,,,
,6.72, 00, 11, 00, 11,6.86, 111, 00, 010,N/A,,,,,
,6.97, 00, 00, 00, 11,7.07, 111, 00, 010,N/A,,,,,
,7.17, 00, 11, 00, 11,7.27, 111, 00, 010,N/A,,,,,
,7.42, 00, 11, 00, 11,7.52, 111, 00, 111,N/A,,,,,
,7.63, 00, 00, 00, 11,7.72, 111, 00, 111,N/A,,,,,
,7.83, 00, 00, 00, 11,7.97, 111, 00, 111,N/A,,,,,
,8.08, 00, 00, 00, 11,8.18, 111, 00, 111,N/A,,,,,
,8.28, 00, 00, 00, 11,8.38, 111, 00, 111,N/A,,,,,
,8.53, 00, 00, 00, 11,8.63, 111, 00, 111,N/A,,,,,
,8.73, 00, 00, 00, 11,8.83, 111, 00, 111,N/A,,,,,
,8.93, 00, 00, 00, 11,9.06, 111, 00, 111,N/A,,,,,
,9.17, 00, 00, 00, 11,9.27, 111, 00, 111,N/A,,,,,
,9.37, 00, 11, 00, 11,9.47, 111, 00, 010,N/A,,,,,
,9.62, 00, 11, 00, 11,9.72, 111, 00, 010,N/A,,,,,
,9.82, 00, 00, 00, 11,9.91, 111, 00, 010,N/A,,,,,
,10.01, 00, 00, 00, 11,10.16, 111, 00, 010,N/A,,,,,
,10.26, 00, 11, 00, 11,10.36, 111, 00, 010,N/A,,,,,
,10.46, 00, 00, 00, 11,10.55, 111, 00, 010,N/A,,,,,
,10.70, 00, 00, 00, 11,10.80, 111, 00, 010,N/A,,,,,
,10.90, 00, 11, 00, 11,11.00, 111, 00, 010,N/A,,,,,
,11.10, 00, 11, 00, 11,11.24, 111, 00, 010,N/A,,,,,
,11.34, 00, 00, 00, 11,11.44, 111, 00, 111,N/A,,,,,
,11.54, 00, 00, 00, 11,11.64, 111, 00, 111,N/A,,,,,
,11.79, 00, 00, 00, 11,11.89, 111, 00, 111,N/A,,,,,
,11.99, 00, 00, 00, 11,12.08, 111, 00, 111,N/A,,,,,
,12.18, 00, 00, 00, 11,12.32, 111, 00, 111,N/A,,,,,
,12.43, 00, 00, 00, 11,12.53, 111, 00, 111,N/A,,,,,
,12.63, 00, 00, 00, 11,12.73, 111, 00, 111,N/A,,,,,
,12.88, 00, 00, 00, 11,12.98, 111, 00, 111,N/A,,,,,
,13.08, 00, 00, 00, 11,13.17, 111, 00, 111,N/A,,,,,
,13.27, 00, 00, 00, 11,13.42, 111, 00, 111,N/A,,,,,
,13.52, 00, 00, 00, 11,13.62, 111, 00, 111,N/A,,,,,
,13.72, 00, 10, 00, 11,13.81, 111, 00, 011,N/A,,,,,
,13.96, 00, 10, 00, 11,14.06, 111, 00, 011,N/A,,,,,
,14.16, 00, 00, 00, 11,14.26, 111, 00, 011,N/A,,,,,
,14.36, 00, 00, 00, 11,14.51, 111, 00, 011,N/A,,,,,
,14.61, 00, 10, 00, 11,14.70, 111, 00, 011,N/A,,,,,
,14.80, 00, 10, 00, 11,14.90, 111, 00, 011,N/A,,,,,
,15.05, 00, 00, 00, 11,15.15, 111, 00, 011,N/A,,,,,
,15.25, 00, 10, 00, 11,15.35, 111, 00, 011,N/A,,,,,
,15.45, 00, 10, 00, 11,15.58, 111, 00, 011,N/A,,,,,
,15.69, 00, 00, 00, 11,15.79, 111, 00, 011,N/A,,,,,
,15.89, 00, 10, 00, 11,15.99, 111, 00, 011,N/A,,,,,
,16.14, 00, 10, 00, 11,16.24, 111, 00, 011,N/A,,,,,
,16.34, 00, 00, 00, 11,16.43, 111, 00, 011,N/A,,,,,
,16.53, 00, 00, 00, 11,16.68, 111, 00, 111,N/A,,,,,
,16.78, 00, 00, 00, 11,16.88, 111, 00, 111,N/A,,,,,
,16.98, 00, 00, 00, 11,17.08, 111, 00, 111,N/A,,,,,
,17.23, 00, 00, 00, 11,17.33, 111, 00, 111,N/A,,,,,
,17.43, 00, 00, 00, 11,17.52, 111, 00, 111,N/A,,,,,
,17.62, 00, 00, 00, 11,17.77, 111, 00, 110,N/A,,,,,
,17.87, 00, 01, 00, 11,17.97, 111, 00, 110,N/A,,,,,
,18.07, 00, 00, 00, 11,18.16, 111, 00, 110,N/A,,,,,
,18.31, 00, 00, 00, 11,18.41, 111, 00, 110,N/A,,,,,
,18.51, 00, 01, 00, 11,18.61, 111, 00, 110,N/A,,,,,
,18.71, 00, 01, 00, 11,18.84, 111, 00, 110,N/A,,,,,
,18.95, 00, 00, 00, 11,19.05, 111, 00, 110,N/A,,,,,
,19.15, 00, 01, 00, 11,19.25, 111, 00, 110,N/A,,,,,
,19.40, 00, 01, 00, 11,19.50, 111, 00, 110,N/A,,,,,
,19.60, 00, 00, 00, 11,19.69, 111, 00, 110,N/A,,,,,
,19.80, 00, 00, 00, 11,19.94, 111, 00, 111,N/A,,,,,
,20.04, 00, 00, 00, 11,20.14, 111, 00, 111,N/A,,,,,
,20.24, 00, 00, 00, 11,20.33, 111, 00, 111,N/A,,,,,
,20.47, 00, 00, 00, 11,20.56, 111, 00, 111,N/A,,,,,
,20.66, 00, 00, 00, 11,20.75, 111, 00, 111,N/A,,,,,
,20.85, 00, 00, 00, 11,21.00, 111, 00, 111,N/A,,,,,
,21.10, 00, 00, 00, 11,21.20, 111, 00, 111,N/A,,,,,
,21.30, 00, 00, 00, 11,21.39, 111, 00, 111,N/A,,,,,

MP4.2+6.0

1. Putting aside any of the codes, the symptoms you describe in terms of the way the lights function sound to me like pretty classic goofed up trailer light wiring as one place to check. That's why I asked if you had a trailer hitch and wiring. Not clear from your reply if the hitch also has trailer wiring with it, but I'm guessing yes. If so, I would certainly look there. For U.S. wiring anyway of the most common type (4 wire), the brighter bulb or filament (used for turn signal flasher and brake lights) is all merged together. The dimmer one for the tail lights is separate, as is the reverse bulb. Ground makes the fourth wire. Thus, if I relate your symptoms to that kind of wiring, it feels like I would be looking there. Hence, look at your trailer electrical connector for any corrosion, shorted wires, etc., look at the wire splices into your car wiring, look at the control module for the trailer (typically there is a module that merges the signal from the tail lights and brake lights on the two sides, presumably with diodes to prevent reverse flow).

2. In the older Audi days of conventional (non-LED) bulbs, this kind of "cross talk" between lighting circuits in the tail lights was kind of notorious. C1's and C2's were plagued with it, as was the original Fox. Saw this many a time personally. It lingered in later ones too, but not nearly as commonly. The usual problem was corrosion and dirt and water ingress at the bulb base in the tail light. With LED's that wouldn't apply, but it would suggest still looking at the basic connector to the light units. You could also look at the wiring harness in the trunk, particularly if it could have been snagged or abraded. I saw this abrasion issue in a C3 where the wiring came through the trunk support into the trunk lid and the repeated opening and closing wore away the insulation. A little fresh electrical tape cured that. Given the D3 recalls of all the early cars for trunk hinge replacement, if you have one of those maybe the wiring got snagged/damaged somehow and is now acting up.

3. All of this is separate from the D3 electronics, where I can see with an optical control system (if it is used here) the chance for problems either in a box up near the dash that would merge all the lighting inputs for digital coding, or back toward the trunk where I would guess they would separate again and be fed voltage to drive the lights. That's where you would want to look at codes, if you don't have the more physical connector/wiring issues like in ##1 or 2.

diebeste

Apparently the previous owner had Netstar fitted (similar to lowjack) and they chose a point close to the convenience controller, and on removal just cut the wires. So now they need to order a new controller and wires. Parts not in stock, obviously.
That would explain the 02200 - Communication Wire to Taillights error at 58km mileage.
So, when I went to collect my car, awaiting the parts delivery, I noticed that they managed to break my boot (trunk :-) auto-close function....
<sigh>
So now I am still stuck with a 2.0 A4 loaner until they sort out the auto-close.