With my 96 TDI I get the ABS error 314 sporadically (ink right wheel sensor signal). The ABS control unit was soldered 3 years ago, so I would almost exclude it as a source of error. 1) With cold soldering point at the control unit came as far as I remember a whole latte of errors. Or can a single error also indicate a defective control unit? 2) What can one check on the sensor at all? Can it also be dirt? As I read, the exchange of this sensor is not quite as easy. The tank must probably be drained.