Diagnostic System Check

Diagnostic System Check - ABS
Circuit Description
The Diagnostic Circuit Check is organized method of identifying any problems caused by a malfunction in the ABS/DDRP system.

A service technician should begin diagnosis of any ABS/DDRP complaint with the Diagnostic Circuit Check. The Diagnostic Circuit Check directs a service technician to the next logical step when diagnosing a complaint.

Serial data is transmitted/received by the Electronic Brake Control Module (EBCM) through terminal 7. The EBCM is supplied with constant battery feed voltage through terminals 9 and 25, and switched ignition voltage through terminal 4. The EBCM ground is provided through terminal 8 and 24.

Diagnostic Aids





Use the following ordered procedure when servicing the ABS/DDRP system.
1. Inspect the vehicle for any mechanical conditions related to the brake system.
^ Verify the Brake reservoir fluid level is correct.
^ Inspect master for fluid contamination.
^ Inspect the brake master/modulator for leaks.
^ Inspect brake components at all wheels.
^ Verify no brake drag exists after brake switch adjustment.
^ Verify even brake application with no pull or lead.
^ Inspect for worn/damaged brake pads.
^ Inspect for worn/damaged wheel bearings.
^ Inspect wheel speed sensor/wiring.
^ Inspect exciter rings for damage.
^ Inspect tires for tread depth/wear.
^ Road test the vehicle to verify the complaint.
2. Perform the Diagnostic System Check and proceed to the applicable diagnostic trouble code as necessary.
3. Clear the ABS DTCs after all of the system malfunctions have been corrected.