Intermittent Diagnostic Trouble Codes

Most intermittent faults are caused by faulty electrical connections or wiring. When an intermittent fault occurs, check the following circuits for:

1. Poor mating of connector halves, or electrical terminals pushed out of connectors.
2. Improperly routed wiring or damaged connectors.
3. Poor terminal to wire contact. This requires removal of the terminal from the connector and inspection terminal to wire connection.

If a visual inspection does not find the cause of the intermittent fault, operate vehicle and attempt to duplicate the fault condition. Most failures will disable the ABS system for the entire ignition cycle even if the fault is cleared. Some failure conditions will allow ABS operation to resume during the ignition cycle in which a failure occurred. The following conditions may result in intermittent illumination of the red brake warning lamp and/or the amber anti-lock warning lap. All other failures will cause the lamp(s) to remain On until the ignition switch is turned Off. Circuits and/or components involving these inputs to the CAB should be inspected.

1. Low system voltage. If low system voltage is detected by the CAB, the CAB will turn the amber anti-lock warning lamp On until normal voltage is restored.
2. Low Brake Fluid. A low brake fluid condition will cause the red brake warning lamp to illuminate. This condition may exists during hard cornering or while the vehicle is on a grade. If the vehicle is in motion above 3 MPH the amber anti-lock warning lamp will also be turned On.
3. Low accumulator pressure. Low accumulator pressure will cause both the red brake warning and amber anti-lock warning lamps to illuminate until normal pressure is restored.
4. Any condition that results in an interruption of power to the CAB or hydraulic assembly may cause the red brake warning or amber anti-lock warning lamps to illuminate.

Any of the conditions mentioned above, can store a fault code in the CAB module.