Self-Diagnostic System

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

When VSA modulator/control unit detects a problem and either indicator light comes on, VSA modulator/control unit will store a DTC. VSA modulator/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) and cannot be erased from memory by disconnecting battery. See CLEARING DIAGNOSTIC TROUBLE CODES  under DIAGNOSIS & TESTING. When 2 or more DTCs are stored in VSA modulator/control unit, trouble shoot DTCs in order of appearance. If complaint cannot be verified, establish conditions present when indicator light came on. If possible, test drive vehicle under similar conditions. If neither indicator light comes on during test drive, check for loose connectors and/or terminals. Shake wiring and connectors while diagnosing. Attempting to follow diagnostic test procedures when indicator is not lit may lead to faulty diagnosis.