RS4 Trailer electrics - installation issue

Hi All,

Just got a 2006 RS4 Cabriolet (fantastic car!!!) anyway, need a towbar so got a Westfalia removable one - fitted it (had to take about 5mm more off the bumper than I would have liked but got it all done and it looks fine (great it can be removed). I only have it for carrying the odd bike - will never be towing a trailer with it - used the original nuts and original holes (drilled a corresponding hole in the towbar as the RS4 has the predrilled trailer holes that are normally covered by a sticker welded over!).

Anyway, since I had the trailer unit and wiring on my B6 2.4 Cab I removed it and installed it in the RS4 (in Etka the part numbers are the same - for the B7 - as is the wiring). connected the comfort bus to the central convenience, the brake wire and the power to the correct fuses (same as I did on the B6).

Coded the instrument panel for trailer as well as ECU 1 and 2.

Anyway couple of issues:

1) when the engine is running I get a load of errors in the instrument panel (TPMS, headlight leveling, headlight cornering) over and over again, these are not logged though in the fault section.

2) If I have the lights on they will sometimes go out for a second and then come back on

3) if the lights are off the interior lights in the car (e.g. aircon) go off for a second and then come back on.

4) If I plug in a light board the rear lights are on continuously, as are the number plate lights. Indicators do not work.

5) I can't remember if unit 69 (Trailer) is accessible in Vagcom or not on the B6, but on the RS4 I can't access it.

6) with the unit powered I get funny results from the central convenience - e.g. no response or if I do it gets no response from the door modules!

Wiring is exactly as on the B6 so happy it is not a wiring issue - interestingly power is provided for fuse 27 AND it is marked on the cover as being for towing!! .

I did notice that the RS4 has the "S" symbol in the dash where the B6 had the towing symbol.

Q. Has anyone managed to get the OEM trailer unit working on a RS4?

Q. if so, how?

Thinking I may have to use a relay instead of the OEM but before I go and rewire (and tap into the rear lights which I would like to avoid) I wanted to see if it is possible to use the original unit!

Thanks

W.