I have a audi 80 1.9tdi 1994 which has just started putting the engine warning "CHECK" light on after a mile or so of driving. touching the brake pedal puts it out. it reappears after another mile or so. Touching the brake pedal puts it out again every time it comes on.
Car has done 146000 miles. no obvious loss of power or problems with engine when the light comes on.
Any ideas what fault may be?
