[mattylondon]

The ACC module (distance control unit J428) is integrated into the radar (distance control sender G259) as one unit behind the bumper. What is the actual fault logged in 13-Distance Control, just the voltage reading?

Can VCDS connect to 13-Dist. Control? It could be a damaged wire to the Radar? My first investigation would be to test the wiring.

You'll have to remove the bumper to access the connector for the radar; with ignition on bridge pins 1 & 12 (T31 & T15) on the plug (NOT RADAR!) with a multimeter - note if there is current by measuring the voltage.

If the above is good now drop the glove box for the connection to the CAN gateway. Create a closed circuit by attaching a multimeter to Pin 2 at radar plug and Pin 13 at gateway plug, this is testing CAN-H. If a closed circuit then CAN-H is good. Now create a closed circuit by attaching a multimeter to Pin 4 at radar and Pin 26 at gateway, this is testing CAN-L.

If all these tests are positive then the wiring is good. Next thing is to test the radar, I can do this on my test bench setup. Let us know how you get on with the above first.