Diagnostic System Check

Diagnostic System Check - ABS

Circuit Description
The Diagnostic System Check is an 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 System Check. The Diagnostic System Check directs a service technician to the next logical step when diagnosing a complaint.

Delphi
Serial data is transmitted/received by the Electronic Brake Control Module (EBCM) through terminal 21 The EBCM is supplied with constant battery feed voltage through terminals 1 and 2, and switched ignition voltage through terminal 13. The EBCM ground is provided through terminal 14 and 15.

Mando
Serial data is transmitted/received by the 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

Steps 1 - 6:

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 the master for fluid contamination.
^ Inspect the brake master/modulator for leaks.
^ Inspect the 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 the wheel speed sensor/wiring.
^ Inspect the exciter rings for damage.
^ Inspect the 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.