VAG 1551 Indicates Error in Communication Link, Checking Wiring Connections

-- Isolate wiring for other vehicle systems with On Board Diagnostic (Rapid data transfer) from white DLC, terminal 2.

Courtesy of AUDI OF AMERICA, LLC

-- Disconnect them one by one from wiring connection -K- (in auxiliary relay panel I).

-- Select "Rapid data transfer" operating mode 1 and insert address word 03 for "Brake Electronics" after each control module is disconnected.

NOTE:

For details of other systems with On Board Diagnostic function

If the Scan Tool then shows ABS control module identification:

-- Check wiring to control module that was disconnected last, using the wiring diagram.

If no malfunction is found in the wiring:

-- Replace control module that was disconnected last.

-- Reconnect all wiring connections.

NOTE:

If the Scan Tool indicates "Control module does not answer" the wiring to the ABS Control Module (w/EDL) -J104- has now also been disconnected.