Diagnostic System Check - ABS

Diagnostic System Check (Part 1 Of 5):

Diagnostic System Check (Part 2 Of 5):

Diagnostic System Check (Part 3 Of 5):

Diagnostic System Check (Part 4 Of 5):

Diagnostic System Check (Part 5 Of 5):

ABS Schematic:

CIRCUIT DESCRIPTION
The Diagnostic System Check is an organized approach to identifying an Antilock Brake System (ABS) malfunction. It must be the starting point for any ABS complaint diagnosis because it directs the service technician to the next logical step in diagnosing the complaint. Serial data is transmitted/received by the EBCM through terminal A1. The EBCM is supplied switched ignition voltage through terminal A9 and battery voltage through terminal B12. The EBCM ground is provided through terminal D.

DIAGNOSTIC AIDS
Excessive resistance in the ground or power supply circuits will not allow communication with the EBCM. If communication with the EBCM is not possible, ensure the ABS ground connection is good and that there is no excessive resistance in any of the power supply circuits.