Self-Diagnostic System

When ABS control unit detects a problem and indicator light comes on, a DTC will be stored in memory. ABS control unit can store any number of DTCs. The DTCs are indicated in order of ascending number. DTCs are memorized in EEPROM (non-volatile memory). DTCs cannot be erased from memory by disconnecting battery. See CLEARING TROUBLE CODES  under DIAGNOSIS & TESTING. When 2 or more DTCs are stored in ABS control unit, trouble shoot DTCs in order of appearance. If complaint cannot be verified, establish conditions present when ABS indicator light came on. If possible, test drive vehicle under similar conditions. If ABS indicator light does not come on during test drive, check for loose connectors and/or terminals. Shake harnesses and connectors while performing diagnosis. Attempting to diagnose system by following diagnostic test procedures when ABS indicator light is not on may lead to faulty diagnosis.

ABS control unit performs 2 self-diagnostic functions. Initial diagnosis is performed from time engine starts until ABS indicator light goes off. Regular diagnosis is continuously performed from time ABS indicator light goes off on start-up until engine stops. When a problem is detected, ABS control unit will turn ABS indicator light on, turn fail-safe relay off and stop ABS control. If system returns to normal while driving (intermittent condition), ABS indicator light may go out when system returns to normal or may stay on until ignition is turned off.