Diagnostic Strategies
Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are:
^ Poor mating of connector halves, or terminals not fully seated in the connector body (backed out).
^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact.
^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector.
^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to 'Checking Terminal Contact' in this section for the specific procedure.
^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, refer to 'Checking Terminal Contact' in this section for specifics.
^ Poor terminal-to-wire connection. Checking this requires removing the terminal from the connector body. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc.
^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle.
^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when mating wiring or terminal repairs.
Most failures of the Antilock Brake System will disable antilock and traction control function for the entire ignition cycle, even if the fault clears before key-off. There is one failure condition, however, which will allow ABS/TCS operation to resume during the ignition cycle in which a failure occurred if the failure conditions are no longer present:
^ Low System Voltage
If low system voltage is detected at the EBTCM, the ABS will turn on the red BRAKE warning lamp and ANTILOCK DISABLED' and 'TRACTION DISABLED' messages until normal system voltage is achieved. Once normal voltage is detected at the EBTCM, normal operation resumes.
Low system voltage may result in intermittent operation of the ANTILOCK DISABLED' and 'TRACTION DISABLED' messages and red BRAKE warning lamp. All other failures will cause the messages and warning lamp to remain on until the ignition switch is turned off and then back on. Circuits involving these inputs to the EBTCM should be investigated if a complaint of intermittent warning system operation is encountered.