Diagnosis & Testing: Notes

NOTE: For more information, see the ANTI-LOCK BRAKE SYSTEM - ABS-VI article in the BRAKES section.

NOTE: Tech 1 scan tester, most current Mass Storage Cartridge (MSC) and High-Impedance Multimeter (J-39200), or equivalent, are required to test parts of ABS.

Before attempting any diagnostic procedures, road test vehicle to verify complaint. Perform pre-diagnostic visual inspection to detect obvious problems. See PRE-DIAGNOSTIC INSPECTION . Repair problems if necessary, and retest vehicle.

If no obvious problem is found, scan ABS for Diagnostic Trouble Codes (DTC). Attach Tech 1 scan tester to Data Link Connector (DLC), and follow Tech 1 scan tester instructions to retrieve DTCs. If DTCs are found, proceed to diagnostic flow charts. Refer to the DIAGNOSTIC CHARTS in this article.

If no DTC is displayed, test drive vehicle while using AUTOMATIC SNAPSHOT feature of Tech 1 scan tester. See SNAPSHOT. If failures cannot be reproduced, use ENHANCED DIAGNOSTIC feature to reveal ABS fault history. See ENHANCED DIAGNOSTICS .