dieselfitter251
Blow ma own trumpet?
Just about to put the new rear ABS sensors, (courtesy of Siena, cheers mate... great service as usual) on the car!! Watch this space for cursin, questions, anxiety and hopefully jubilation!
ABS light is an MOT fail mate.
I think you need to stop messing around with this duff ECU and get yourself another one. I suspect there MAY be another fault, that the faulty ECU is just not managing to record, however its going to take a working ECU to find it.
One last thing that might work, is if you start the car, drive until you get the (!), then check the fault codes without shutting the engine off. If the memory in the ECU is faulty, but the ECU works, then you might get the codes out of it while they're still "fresh" as it were.
http://cgi.ebay.co.uk/Audi-A4-2-6l-Quattro-BOSCH-ABS-ECU-MODULE_W0QQitemZ200322121939QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item200322121939&_trksid=p3286.c0.m14&_trkparms=66:2|65:1|39:1|240:1318|301:0|293:1|294:50
dunno if all quattros ecus are the same?
diesel, the other common issue is the reluctor ring becoming corroded so the ABS sensor cant pick up the signal. Fixing that requires new rear CV joints afaik.
Thats also possible to be the cause of intermittent ABS firing as in Geemans case.