OK. That's curious, but worth looking at. It certainly feels like the rear diff has wound up. Like on the ur-quattro, when the rear diff is locked.

However, I hadn't even considered that the ABS ECU had any direct input to the transmission ECU. ya learn something new everyday.

Cheers

85 WR quattro
90 V8 Silver, 91 V8 Black, 93 V8 Lago
93 100e quattro V6. Titan, i think