ABS light stays on

We need the code to further help you

Roy

If the light is on, there is a code. It will not show on the engine side, it will show with a code reader that reads abs

Roy

DTC C0221-C0227 or C021

Circuit Description

As the wheel spins, the wheel speed sensor produces an AC signal. The electronic brake control module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.

Conditions for Running the DTC

C0221 and C0225

The ignition is ON.

C0222, C0223, C0226 and C0227

The vehicle speed is greater than 32 km/h (20 mph) when the brake is applied or 19 km/h (12 mph) when the brake is released.

Conditions for Setting the DTC

C0221 and C0225

The EBCM detects an open or shorted wheel speed sensor or wheel speed sensor circuit for 500 milliseconds.

C0222 and C0226

The corresponding wheel speed sensor signal is less than 6 km/h (4 mph) for 5 seconds, or 120 seconds in order to set both DTCs.

C0223 and C0227

The EBCM detects an erratic signal from the corresponding wheel speed sensor for 105 milliseconds.

Action Taken When the DTC Sets

C0221 and C0225

If equipped, the following actions occur:

†The EBCM disables the ABS/traction control system (TCS).
†The ABS indicator turns ON.
†The TRACTION OFF indicator turns ON.
C0222, C0223, C0226 and C0227

If equipped, the following actions occur:

†The EBCM disables the ABS/TCS and may disable dynamic rear proportioning (DRP).
†The ABS indicator turns ON.
†The TRACTION OFF indicator turns ON.
†The red Brake warning indicator may turn ON.
Conditions for Clearing the DTC

†Repair the condition responsible for setting the DTC.
†Use a scan tool in order to clear the DTC.
†After the DTC is cleared and the ignition is ON, the ABS indicator may remain ON until the EBCM completes a power-up self-test. This test concludes when the vehicle reaches a speed greater than 13 km/h (8 mph) and the wheel speeds are verified by the EBCM.
Diagnostic Aids

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 the following:

†Testing for Intermittent Conditions and Poor Connections
†Connector Repairs
†Testing for Electrical Intermittents
†Wiring Repairs
If the customer 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:

1. Spray the suspected area with a 5 percent salt water solution.
2. 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.

3. Measure the resistance of the wheel speed sensor in order to determine if the sensor has a valid resistance value.
4. Ensures that the wheel speed sensor is generating a valid AC voltage output.