Symptom Troubleshooting Index

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

TROUBLESHOOTING CHART

Symptom	Diagnostic procedure	Also check for
HDS does not communicate with the ABS modulator-control unit or the vehicle	Troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
ABS indicator, brake system indicator (red), and brake system indicator (amber) do not come on	Do the gauge control module troubleshooting (see SELF-DIAGNOSTIC FUNCTION ). Substitute a known-good ABS modulator-control unit, then recheck. If it is OK, replace the original ABS modulator-control unit (see ABS MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ).
ABS indicator, brake system indicator (red), and brake system indicator (amber) do not go off	Check for F-CAN DTCs, and troubleshoot and repair those first. Do the gauge control module troubleshooting (see SELF-DIAGNOSTIC FUNCTION ). Symptom Troubleshooting, (see SYMPTOM TROUBLESHOOTING ).