Graham,

Was your ABS pump running constantly along with the ABS, BAS & ESP lights indicating a malfunction? I now see where some of the confusion in coming from. There is a relay #A 002 542 13 19 on the unit I am calling the K40 relay on the passenger side of the car. The relay that I ultimately replaced that fixed the problem was also #A 002 542 13 19 but it was behind the fuse box on the driver's side. We determined that it was causing the problem because when it was pulled with the ABS pump running, the pump stopped.

I have attached photos of the fuse box covered, with the cover off, and with a close up of the back section containing a number of relays. There are six screws that need to be removed to get the cover off. The relay #A 002 542 13 19 is the black one on the right side in image 924. If your pump runs constantly, try pulling this relay to see if it stops.

I also dug out my spare parts and compared the #A 002 542 13 19 original relay to the # A 002 542 72 19 64 that is supposed to be a replacement number. The size and prongs look the same but the plastic cases have different attachment tabs. The tabs aren't used in either location but I wonder if these numbers are actually interchangeable.

Attached Thumbnails