well im no better off! went to a local merc garage and he put it on the proper merc computor no faults!,re bled the system went back to work and used the rolling road hand brake fine, left efort nill,right efort nill, balence (both together) fine!.hand brake fine,put another master cyl on still no change!,un pluged pressure sens on top of abs unit and it worked fine!!but the abs light come's on so no mot!.its as if the abs thinks the wheel is skidding and is ristricting the flow?.could both hub teeth be worn or sensors not working right?,it has to be some form of abs fult as they work fine with the engine off!!