Self-Diagnostic System

ABS/TCS 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/TCS control unit will turn ABS or TCS indicator light on, turn fail-safe relay off and stop ABS or TCS control. If system returns to normal while driving (intermittent condition), ABS or TCS indicator light may go out when system returns to normal or may stay on until ignition is turned off.

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