Trouble Shooting: Notes

NOTE: If system is not functioning properly after all testing procedures have been completed, substitute known-good ABS ECU and retest.

When diagnosing a problem with ABS system, start by gathering information about he problem from customer. Verify condition described by customer exists. Check vehicle for any ABS DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES . If you can verify that a malfunction exists, but there are no ABS DTCs, or system cannot communicate with MUT-II (MB991502) or equivalent scan tool, check to see if basic brake system is operating properly. If basic brake system is not operating properly, refer to DISC & DRUM article.