Diagnostic Aids

WARNING: This page is about a different car, the 2003 GMC Sonoma, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.

Operating the vehicle on extremely rough terrain can set DTC C0223, C0227 or C0229 even if the system is functioning normally.

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS , CONNECTOR REPAIRS , TESTING FOR ELECTRICAL INTERMITTENTS and to WIRING REPAIRS in Wiring Systems.

If the customer's concern is that the ABS indicator is on only during humid conditions such as rain, snow or vehicle wash, thoroughly inspect the wheel speed sensor circuits for signs of water intrusion. Use the following procedure in order to help isolate the problem area:

Spray the suspected area with a 5 percent salt water solution.
Drive the vehicle at a speed greater than 19 km/h (12 mph) for at least 30 seconds.
Repair or replace the suspect harness if the DTC sets.

Test Description

The numbers below refer to the step numbers on the diagnostic table.
Measure the resistance of the wheel speed sensor in order to determine if the sensor has a valid resistance value.
Ensures that the wheel speed sensor is generating a valid AC voltage output.

Fig 1: DTC C0221-C0227 - Diagnostic Procedure Table (Steps 1 & 2)

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC C0221-C0227 - Diagnostic Procedure Table (Steps 3-10)

Courtesy of GENERAL MOTORS CORP.