Jon Andrews

So after some extensive investigation I have information on the Audi Factory Hitch for '02 A4 Avants including part numbers for all the pieces. The two interesting factors are;

1. Dealer claims that Audi allocates 8hrs to install but in fact no hitch has been installed at this dealership in less than 12 hrs.

2. The install requires a 're-programming' of the ECU.

The key questions are obviously.....A) What takes 12hrs to complete? That amount of time implies that practically the whole rear end of the car has to be disassembled, and B) Why does the ECU need to be re-programmed?

The only logical explanation I can come up with is that on an Auto(TIP) the shift points/engine fuel mapping may be changed when the hitch is in operation, but doesn't this happen automatically based on engine load the ECU 'sees'?

Anyone care to fill in the blanks on the abpove questions?

Incidentally the complete hitch package including wiring is about $375 from a dealer, although I suspect that outher OEM parts distributors could do better.

Currently my idea is to obtain the mechanical parts for the hitch and then install a US wiring harness without the ECU complications which would only be an approximate $300 solution.

Thanks,

woofpup

It's hard to say what the ECU reprogramming is for. It could be to adjust the ESP for handling itself differently due to a large object being attached to the rear of the car. Things like changing the manner in which the ECU handles heavy load, etc. should be like that stock.

Unfortunately, if the factory hitch isn't available in the U.S., that ECU program they put it probably isn't either. The UK's ECU programs might not work on U.S. cars due to emissions differences, etc.