TROUBLESHOOTING
See appropriate DISC article.
PRE-DIAGNOSIS INSPECTION
Perform a comprehensive visual inspection of components that could create an ABS malfunction. Visually inspect all wiring and connectors. Ensure speed sensors are clean and connections are tight. Check brake lines for correct line routing. Check for hydraulic leaks. Ensure battery is fully charged and terminals are clean and tight.
TEST EQUIPMENT
BMW Service Tester is used to check functions of the ECU, hydraulic unit, wire harness and related groups of the ABS system. Actual values determined with the service tester must correspond with values given.
DIAGNOSTIC PROCEDURE (5 & 7-SERIES)
Check ABS when ABS indicator light does not go out, comes on while driving, does not come on when turning on the ignition or when servicing the ABS.
The ABS is checked with the BMW Service Tester. Connect wire harness and ECU using the ABS plug. Each test step started MUST be finished completely without interruption.