Chassis Diagnostic Procedures - Anti-Lock Brake System: Introduction: Notes

The procedures contained in this service information include all the specifications, instructions, and graphics needed to diagnose the Mark 20e and Mark 25e Antilock Braking Systems (ABS)  . The diagnostics in this service information are based on the failure condition or symptom being present at time of diagnosis.

Please follow the recommendations below when choosing your diagnostic path.

1. First make sure the DRBIII® is communicating with the Controller Antilock Brake (CAB) or Anti-Lock Brake Module (ABM). If the DRBIII® displays a "No Response" condition, you must diagnose that first.
2. Read and record DTC's (diagnostic trouble codes) and Freeze Frame information with the DRBIII®.
3. If no DTC's are present, identify the customer complaint.
4. Once the DTC or customer complaint is identified, locate the matching test in DIAGNOSTIC INFORMATION AND PROCEDURES  and begin to diagnose the symptom.

All component location views are in COMPONENT LOCATIONS . All connector pinouts are in CONNECTOR PINOUTS . All schematics are in SCHEMATIC DIAGRAMS .

An asterisk (*) placed before the symptom description indicates a concern with no associated DTC.

When repairs are required, refer to the appropriate service information for the proper removal and repair procedure.

Diagnostic procedures change every year. New diagnostic systems may be added; carry over systems may be enhanced. READ THIS SERVICE INFORMATION BEFORE TRYING TO DIAGNOSE A VEHICLE CODE. It is recommended that you review the service information to become familiar with all new and changed diagnostic procedures.