Diagnostic Circuit Check

Diagnostic Chart:

The Diagnostic Circuit Check is an organized approach to identifying a problem created by 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.

The "scan data" listed in the table may be used after completing the Diagnostic Circuit Check and finding the on-board, diagnostics functioning properly and no Diagnostic Trouble Codes displayed.

A TECH 1 THAT DISPLAYS FAULTY DATA SHOULD NOT BE USED, AND THE PROBLEM SHOULD BE REPORTED TO THE MANUFACTURER. THE USE OF A MALFUNCTIONING TECH 1 CAN RESULT IN MISDIAGNOSIS AND UNNECESSARY PARTS REPLACEMENT.

Only the parameters listed below are used in this manual for diagnosing. If a scan tool other than Tech 1 is used and reads other parameters, the values are not recommended by General Motors for use in diagnosing.