Symptom Chart

Condition	Possible Sources	Action
No communication with the ABS module	Wiring, terminals or connectors ABS module	REFER to MODULE COMMUNICATIONS NETWORK article to diagnose the no communication problem.
The red brake warning indicator and the yellow ABS warning indicator are always on	DTCs present in the ABS module	RETRIEVE and RECORD the DTCs. Go to the ABS MODULE DTC INDEX .
The red brake warning indicator is on and the yellow ABS warning indicator is not on	Brake fluid level low and/or brake fluid leaks Brake fluid level switch Parking brake switch Wiring, terminals or connectors Instrument cluster	Refer to Diagnosis and Testing in BRAKE SYSTEM - GENERAL INFORMATION article.
The yellow ABS warning indicator does not self-check	Wiring, terminals or connectors Instrument cluster ABS module	REFER to INSTRUMENT CLUSTER (IC) & WARNING CHIMES article.
The yellow ABS warning indicator self-checks OK but automatically begins flashing	Wiring, terminals or connectors ABS module HCU	RETRIEVE and RECORD the DTCs. Go to the ABS MODULE DTC INDEX .