Symptom Chart

SYMPTOM CHART

Condition	Possible Sources	Action
No communication with the ABS module	Wiring, terminals or connectors ABS module	REFER to MODULE COMMUNICATIONS NETWORK to diagnose the no communication concern.
The ABS warning indicator is always/never on	Wiring, terminals or connectors ABS module Instrument Panel Cluster (IPC)	REFER to INSTRUMENTATION, MESSAGE CENTER, AND WARNING CHIMES to continue diagnosis of the warning indicator.
The red brake warning indicator is always/never on	Wiring, terminals or connectors Parking brake switch Brake fluid level switch (part of the master cylinder) IPC	REFER to INSTRUMENTATION, MESSAGE CENTER, AND WARNING CHIMES to continue diagnosis of the warning indicator.
The stability/traction control indicator (sliding-car icon) is always/never on	ABS module PCM IPC Wiring, terminals or connectors Traction control switch	REFER to INSTRUMENTATION, MESSAGE CENTER, AND WARNING CHIMES to continue diagnosis of the warning indicator.
The stability/traction control indicator (sliding-car icon) is flashing at all times	NOTE: It is normal for the indicator to flash during a traction control event. ABS module not configured ABS/ESC system not initialized	RETRIEVE and RECORD all ABS module DTCs and GO to the ABS MODULE DTC CHART .
The traction control system cannot be disabled/enabled	Fuse Wiring, terminals or connectors Traction control switch PCM	GO to PINPOINT TEST L .
The traction control system is inoperative	Traction control system is turned off Traction control system is not configured Fuse Wiring, terminals or connectors ABS wheel speed sensor fault High Speed Controller Area Network (HS-CAN) bus fault PCM IPC Traction control switch	GO to PINPOINT TEST L .
ABS false activation, ABS too sensitive or ABS activates on a normal stop	DTCs present in the ABS module	CARRY OUT the ABS module self-test. RETRIEVE and RECORD the ABS module DTCs. GO to the ABS MODULE DTC CHART .
	Brake pads Brake calipers and/or guide pins	ELIMINATE the base brake system as the cause of the problem. REFER to DIAGNOSIS AND TESTING .
	Parking brake shoes out of adjustment (dragging)	CHECK and if necessary, ADJUST the parking brake shoes. REFER to PARKING BRAKE AND ACTUATION .
	Front wheel speed sensor rings	INSPECT both front wheel speed sensor rings for damaged teeth. CHECK the wheel speed sensor gap.
	Wheel speed sensors	GO to PINPOINT TEST E .
Vehicle pulls during braking	Brake pads Brake discs Brake calipers and/or guide pins Wheel speed sensor	REFER to BRAKE SYSTEM - GENERAL INFORMATION to diagnose the base braking system.
One or more wheel(s) lock up	Brake pads Brake calipers and/or guide pins	ELIMINATE the base brake system as the cause of the problem. REFER to DIAGNOSIS AND TESTING .
	Parking brake shoes out of adjustment (dragging)	CHECK and if necessary, ADJUST the parking brake shoes. REFER to PARKING BRAKE AND ACTUATION .
	Hydraulic outlet (dump) valve Leaky inlet (isolation) valve during ABS (soft)	BLEED the HCU . REFER to BRAKE SYSTEM BLEEDING . TEST the system for normal operation. If the symptom returns, INSTALL a new Hydraulic Control Unit (HCU). REFER to HYDRAULIC CONTROL UNIT (HCU) .
	Brake tubes are installed in the wrong locations	VERIFY the correct installation of each brake tube and REPAIR as needed.
Soft/excessive brake pedal travel	Air in brake system Brake calipers and/or guide pins Brake flexible hose Brake master cylinder Brake pads Brake pedal	ELIMINATE the base brake system as the cause of the problem. REFER to DIAGNOSIS AND TESTING .
Soft/excessive brake pedal travel	Inlet (isolation) valve or hydraulic outlet (dump) valve Leaky inlet (isolation) valve during ABS applications (soft)	BLEED the HCU . REFER to BRAKE SYSTEM BLEEDING . TEST the system for normal operation. If the symptom returns, INSTALL a new HCU . REFER to HYDRAULIC CONTROL UNIT (HCU) .