Symptom Chart

SYMPTOM CHART

Condition	Possible Sources	Action
No communication with the module - anti-lock brake control module	Central junction box (CJB) fuse 15 (5A). Circuitry. Anti-lock brake control module.	Go To PINPOINT TEST A .
Loss of sensor signal during vehicle deceleration or sensor signal drops out at low speed	Anti-lock brake sensor indicator. Sensor output is weak. Air gap.	Go To PINPOINT TEST D .
Unwarranted anti-lock brake system (ABS) activity	Circuitry. Anti-lock brake sensor.	Go To PINPOINT TEST D .
Maladjusted rear brakes or "grabby" brake shoe or pad linings	Rear brake adjustment. Linings.	REFER to DISC & DRUM .
Base brake mechanical concern for wheels lockup	Rear brake shoe linings. Wheel cylinder. Rear brakes. Parking brake. Rear axle seal.	REFER to DISC & DRUM . REFER to DISC & DRUM . REFER to DIFFERENTIALS & AXLE SHAFTS - REAR .
Base brake hydraulic concern (soft pedal)	Brake line or hose, fitting, master cylinder, wheel cylinder or caliper. Air in brake system.	REFER to DISC & DRUM .
Base brake mechanical concern (hard pedal)	Vacuum boost. Wheel cylinder or caliper. Brake line or hose.	REFER to DISC & DRUM .
Base brake hydraulic concern during medium/hard brake application	Brake line or hose, fitting, master cylinder, wheel cylinder or caliper. Air in brake system.	REFER to DISC & DRUM .
Base brake mechanical concern during medium/hard brake application	Vacuum boost. Wheel cylinder or caliper. Brake line or hose. Brake shoe or pad linings.	REFER to DISC & DRUM .
Base brake mechanical concern for vehicle pulls	Rear brake. Caliper. Brake pad or shoe wear.	REFER to DISC & DRUM .
Base brake hydraulic concern for vehicle pulls	Brake line or hose.	REFER to DISC & DRUM .
One wheel locks up; no DTCs recorded	Base brake. Dump valve. ISO valve.	REFER to DISC & DRUM . INSTALL a new electronic hydraulic control unit. REFER to HYDRAULIC CONTROL UNIT .
The anti-lock brake system (ABS) warning indicator does not self check	Bulb. Circuitry. Instrument cluster. Anti-lock brake control module.	Go To PINPOINT TEST F .
Soft or excessive brake pedal	Brake line or hose, fitting, master cylinder, wheel cylinder, wheel cylinder or caliper. Air in brake system. Hydraulic control unit (HCU).	REFER to DISC & DRUM .
Anti-lock brake system (ABS) warning indicator always on, no DTC	Circuitry. Module.	Go To PINPOINT TEST G .
Red brake warning indicator always on	Instrument cluster. Circuit 603 (DG). Parking brake. Brake fluid level.	Go to INSTRUMENT PANEL .