The On-Board Diagnostic System

The brake system is monitored by the Controller - Antilock Brake (CAB).
- The CAB monitors critical input and output circuits within the antilock brake system of the vehicle, making sure they are operating correctly.
- Some circuits are tested continuously; others are checked only under certain circumstances.

Each circuit monitored by the CAB has a corresponding trouble code assigned to it. Refer to Description and Operation/Diagnostic Trouble Codes for a list and definition of trouble codes. Testing and Inspection
- If the on-board diagnostic system senses that one of the circuits is malfunctioning, it stores the corresponding trouble code in memory.
- If the malfunction goes away after the trouble code is stored, the trouble code will be erased after 50 key cycles.

NOTE: Trouble codes may be accessed by connecting a suitable scan tool to the diagnostic connector.