Pre-Diagnostic Inspection

When checking potential ABS system faults, check following before using DIAGNOSTIC TROUBLE CODE (DTC) CHARTS:

1. Check fuses No. 5, 11 and 37 in main fuse block.
2. Check fusible link to brake pressure modulator.
3. Ensure Electronic Brake Control Module (EBCM) connector is fully seated and tight.
4. Ensure parking brake switch is functioning properly.
5. Check ABS ground circuit for clean tight connections. Ground is located on front of left cylinder head.
6. Always perform ABS system functional check before using DIAGNOSTIC TROUBLE CODE CHARTS. See Fig 1.

Fig 1: Anti-Lock Brake System Functional Check

Courtesy of GENERAL MOTORS CORP.