Symptom Troubleshooting Index

When the vehicle has one of these symptoms, check for a diagnostic trouble code (DTC) with the HDS. If there is no DTC, do the diagnostic procedure for the symptom, in the sequence listed, until you find the cause.

SYMPTOM TROUBLESHOOTING

Symptom	Diagnostic procedure
HDS does not communicate with the VSA modulator-control unit or the vehicle	Troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
ABS indicator does not come on	Do the gauge control module troubleshooting (see SELF-DIAGNOSTIC FUNCTION ). Substitute a known-good VSA modulator-control unit, then recheck. If it is OK, replace the original VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ).
ABS indicator or VSA indicator does not go off, and no DTCs are stored	Symptom Troubleshooting (see SYMPTOM TROUBLESHOOTING ). Do the gauge control module troubleshooting (see SELF-DIAGNOSTIC FUNCTION ).
Brake system indicator does not come on	Do the gauge control module troubleshooting (see SELF-DIAGNOSTIC FUNCTION ). Substitute a known-good VSA modulator-control unit, then recheck. If it is OK, replace the original VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ).
Brake system indicator does not go off, and no DTCs are stored	Symptom Troubleshooting (see BRAKE SYSTEM INDICATOR DOES NOT GO OFF, AND NO DTCS ARE STORED ). Do the gauge control module troubleshooting (see SELF-DIAGNOSTIC FUNCTION ).
VSA indicator does not come on	Do the gauge control module troubleshooting (see SELF-DIAGNOSTIC FUNCTION ). Substitute a known-good VSA modulator-control unit, then recheck. If it is OK, replace the original VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ).
VSA activation indicator does not come on at start-up (bulb check)	Do the gauge control module troubleshooting (see SELF-DIAGNOSTIC FUNCTION ). Substitute a known-good VSA modulator-control unit, then recheck. If it is OK, replace the original VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ).
VSA activation indicator does not go off, and no DTCs are stored	Symptom Troubleshooting (see VSA ACTIVATION INDICATOR DOES NOT GO OFF, AND NO DTCS ARE STORED ). Do the gauge control module troubleshooting (see SELF-DIAGNOSTIC FUNCTION ). Substitute a known-good VSA modulator-control unit, then recheck. If it is OK, replace the original VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ).
ABS indicator, brake system indicator, and VSA indicator do not go off at the same time	Symptom Troubleshooting (see ABS INDICATOR, BRAKE SYSTEM INDICATOR, AND VSA INDICATOR DO NOT GO OFF AT THE SAME TIME ). Do the gauge control module troubleshooting (see SELF-DIAGNOSTIC FUNCTION ).