Hi,
1st. sorry for not making a proper presentation post (I promise I'll do one... soon!), I've been following the forum for almost a year (since I bought my A3).
A few weeks ago I had the same problem; the ABS light came on, in my case, when I switched off the engine and back on, it went till I accelerated above 25/30 km/h (do the math!). I plugged my Ebay cheapo OBDII reader and got this error;
"01276 - ABS Hydraulic Pump (V64) Signal Outside Specifications"
Don't sure if this is the same error you get.
I googled for this error, at first all the solutions were similar; "replace ABS control unit". Not a good option, too expensive anywhere, ridiculously expensive here (in Buenos Aires).
Then I found a post in an American forum (about a Golf mk.4), this guy said he got rid of a similar problem by just reseating the ABS fuses on top of the battery.
Sounded too good (and simple and cheap!
) to be true, but I rushed to the car and found one of these to be actually a bit loose and the socket it sat on was a bit melted (I guess a bad connection resulted in short, thus in heat). I removed the 3 fuses, cleaned these and the seats with light sandpaper, slightly twisted the legs of the "offended" fuse to force good contact points. Plugged my cheap OBDII again to clear the error, and went for a quick and brutal test drive (kept the ABS working like crazy!!
)
All worked perfectly! It's like this for the last 10 days or so.
Later I received the Haynes manual (I know; these stink, but I'm not aware of any better one for the 8L) and in the ABS section it mentions the systems disables itself under different conditions, one of these is low or irregular voltage, which fits the bill of a loose fuse.
I know others had a bad solder point in the ABS circuit, a common VW/Audi fault, but start checking this, leaving the entire replacement as the last resort.
Cheers
Abel