Diagnostic System Check

Circuit Description
The ABS Diagnostic System Check is an organized approach to identify problems associated with the EBCM. This check must be the starting point for any EBCM complaint, and will direct you to the next logical step in diagnosing the complaint. The EBCM is a very reliable component and is not likely the cause of the malfunction. Most system complaints are linked to faulty wiring, connectors, and occasionally to components. Understanding the ABS system and using the tables correctly will reduce diagnostic time and prevent unnecessary parts replacement.
Diagnostic serial data is transmitted/received by the EBCM through connector C1, terminal B6. The EBCM is supplied battery voltage through connector C2, terminal B and switched ignition voltage through connector C1, terminal A1. Ground is provided through connector C2, terminal A.

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 that the ABS ground connection is good and that there is no excessive resistance in any of the power supply circuits.