Diagnostic Aids

Thoroughly inspect the wiring and connectors when diagnosing intermittent DTCs. This will include the following:

• Removal of the protective conduit and inspection of wiring for damage, shorts, and contamination
• Inspection for improperly formed and/or damaged terminals
• Checking terminal contact retention force by using a spare male/female terminal
• Removal of the terminals from the connectors to check for proper terminal to wire crimp

If the driver comments reflect that the ABS warning lamp is ON only during moist environmental changes, such as, rain, snow, vehicle wash, the all wheel speed sensor circuitry should be thoroughly inspected for signs of water intrusion. If the DTC is not current, simulate the effects of water intrusion. Use the following procedure. Spray the suspected area with a 5 percent salt-water solution. Then test-drive the vehicle over various road surfaces such as, bumps, turns, etc., above 24 km/h (15 mph). If the DTC sets then replace the suspected harness and/or sensor.

When measuring the wheel speed sensor resistance, ensure the vehicle is at room temperature, since resistance will increase with temperature.

Failure to perform the previous steps carefully and fully can result in misdiagnosis, unnecessary component replacement, and reoccurrence of DTC C1203.