Symptom Chart

WARNING: This page is about a different car, the 2009 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.

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 communications concern.
No communication with the instrument cluster	Wiring, terminals or connectors Instrument cluster	REFER to MODULE COMMUNICATIONS NETWORK to diagnose the no communication concern.
The yellow ABS warning indicator is illuminated	DTCs in the ABS module	RETRIEVE and RECORD any ABS module DTCs. Go to the ABS Module DTC Chart.
The yellow ABS warning indicator is never on	Wiring, terminals or connectors Instrument cluster	REFER to INSTRUMENT CLUSTER (IC), MESSAGE CENTER, AND WARNING CHIMES to continue diagnosis of the yellow brake warning indicator.
Spongy/soft/low brake pedal with no warning indicator	Air in brake hydraulic system Base brake system Hydraulic Control Unit (HCU)	Go to Pinpoint Test F .
Poor vehicle tracking during anti-lock function	Air in the brake system Base brake system HCU	Go to Pinpoint Test G .
The traction control system is inoperative	Wiring, terminals or connectors Traction control switch Instrument cluster ABS module	Go to Pinpoint Test I .
The traction control system cannot be disabled	Wiring, terminals or connectors Traction control switch Instrument cluster ABS module	Go to Pinpoint Test H .
The traction control switch indicator is never/always on	Circuitry Traction control switch Instrument cluster	REFER to Diagnosis and Testing in INSTRUMENT CLUSTER (IC), MESSAGE CENTER, AND WARNING CHIMES to diagnose the traction control indicator.