Initial Inspection and Diagnostic Overview

Problems related to the Anti-Lock Brake System (ABS) can be classified into two general categories; problems in the electrical system and those in the hydraulic system.
For problems in the electrical system, the self-diagnostic function is built into the Electronic Control Unit (ECU) causing the ABS warning lamp to illuminate as a warning to the driver. In this instance, checks can be made by using the multi use tester and an oscilloscope or by the ABS warning lamp.
Problems with the hydraulic system can be located in the same manner as ordinary brakes. There is, however, the necessity to check to determine whether the problem is related to ordinary brake components or to the components related to the ABS.
In either case, refer to SYSTEM DIAGNOSIS.