Symptom Chart

Condition	Possible Sources	Action
No communication with the anti-lock brake system (ABS) module	Fuse Circuitry ABS module	REFER to MODULE COMMUNICATIONS NETWORK article to diagnose the no communication problem.
No communication with the instrument cluster	Circuitry Instrument cluster	REFER to INSTRUMENT CLUSTER article to continue diagnosis of the instrument cluster.
The red brake warning indicator does not self-check	Instrument cluster	REFER to INSTRUMENT CLUSTER article.
The red brake warning indicator stays on when the ignition switch is in RUN	Circuitry Low brake fluid warning switch Parking brake switch Instrument cluster	REFER to INSTRUMENT CLUSTER article.
The yellow anti-lock brake system (ABS) warning indicator is always on	Circuitry Instrument cluster ABS module	Go to Pinpoint Test G .
Spongy brake pedal with no warning indicator	Air in the brake hydraulic system	Go to Pinpoint Test H .
Poor vehicle tracking during anti-lock function	Air in the hydraulic brake system Hydraulic control unit (HCU)	Go to Pinpoint Test I .
	Base brake system	REFER to BRAKE SYSTEM - GENERAL INFORMATION article.
The traction control is inoperative	Circuitry Traction control switch ABS module Differential electronic module (DEM) Instrument cluster	RETRIEVE and RECORD any DTCs from the ABS module. If DTCs are present, REFER to the Anti-Lock Brake System (ABS) Diagnostic Trouble Code (DTC) Index. If DTCs are not present in the ABS module, RETRIEVE and RECORD any DTCs from the DEM. If DTCs are present, REFER to DRIVELINE SYSTEM - GENERAL INFORMATION article to continue diagnosis of the DEM. If DTCs are not present in the DEM, RETRIEVE and RECORD any DTCs from the instrument cluster. If DTCs are present, REFER to INSTRUMENT CLUSTER article to continue diagnosis of the instrument cluster. If DTCs are not present in the instrument cluster, go to Pinpoint Test K .
The traction control system cannot be disabled	Circuitry Traction control switch Instrument cluster	Go to Pinpoint Test J .
The traction control switch indicator is never/always on	Circuitry Traction control switch ABS module DEM Instrument cluster	RETRIEVE and RECORD any DTCs from the ABS module. If DTCs are present, REFER to the Anti-Lock Brake System (ABS) Diagnostic Trouble Code (DTC) Index. If DTCs are not present in the ABS module, RETRIEVE and RECORD any DTCs from the DEM. If DTCs are present, REFER to DRIVELINE SYSTEM - GENERAL INFORMATION article to continue diagnosis of the DEM. If DTCs are not present in the DEM, RETRIEVE and RECORD any DTCs from the instrument cluster. If DTCs are present, REFER to INSTRUMENT CLUSTER article to continue diagnosis of the instrument cluster. If DTCs are not present in the instrument cluster, go to Pinpoint Test K .