C0228

DTC C0220-C0229

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors
DTC C0220 00
- Left Front Antilock Brake System (ABS) Channel in Release Too Long

DTC C0221 00
- Right Front Antilock Brake System (ABS) Channel in Release Too Long

DTC C0222 00
- Rear Antilock Brake System (ABS) Channel in Release Too Long

DTC C0223 00
- Left Front Antilock Brake (ABS) Channel Motor Free Spins

DTC C0224 00
- Right Front Antilock Brake (ABS) Channel Motor Free Spins

DTC C0225 00
- Rear Antilock Brake System (ABS) Channel Motor Free Spins

DTC C0226 00
- Left Front Traction Control System (TCS) Channel Will Not Move

DTC C0227 00
- Right Front Traction Control System (TCS) Channel Will Not Move

DTC C0228 00
- Left Rear Antilock Brake System (ABS) Channel in Release Too Long

DTC C0229 00
- Right Rear Antilock Brake System (ABS) Channel in Release Too Long

Circuit/System Description

The system relay is energized when the ignition is ON. The system relay supplies voltage to the valve relay. The electronic brake control module (EBCM) activates the valve relay to supply voltage to the valve solenoids. This voltage is referred to as the system voltage. The EBCM microprocessor activates individual valve solenoids by grounding the valve solenoid control circuits. The power brake pump motor is internal to the brake pressure modulator valve (BPMV). The pump motor is not serviceable.

Conditions for Running the DTC

* The system and ignition voltage is greater than 8 volts.
* The system is in an ABS braking event.

Conditions for Setting the DTC

The EBCM commands a dump or isolation solenoid ON for greater than 28 seconds.

Action Taken When the DTC Sets

* The EBCM disables the ABS/Traction Control System (TCS).
* A DIC message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

* The condition for the DTC is no longer present and you can use the scan tool clear DTCS function.
* The EBCM automatically clears the history DTC when a current DTC is not detected in 50 consecutive drive cycles.

Diagnostic Aids

The most likely cause of this DTC is a mechanical failure that causes a wheel to lock and remain locked. Always diagnose and repair any wheel speed sensor failures prior to diagnosing DTCs C0220, C0221, C0228, C0229. These DTCs in theory may be set on surfaces that are nearly impossible to get traction on. If the DTC sets within these conditions, diagnosis of the ABS system may not be necessary.

Reference Information
Schematic Reference

Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems
Description and Operation

ABS Description and Operation Description and Operation
Connector End View Reference

Component Connector End Views Connector End Views By Name
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the EBCM.
2. Test for less than 5 ohms of resistance between the ground circuit terminals listed below and ground.

* Terminal 16
* Terminal 29

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the Pump Motor supply voltage circuit terminal 1 and ground.

• If the test lamp does not illuminate, test the voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit ABS 2 fuse is open test or replace the brake pressure modulator valve (BPMV).

4. Connect the harness connector at the EBCM.
5. Ignition ON, use the scan tool to perform the ABS Motor test.

• If the motor test failed, replace the EBCM.

6. If all circuits test normal, replace the BPMV.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Brake Pressure Modulator Valve Replacement Service and Repair
* Control Module References Control Module References for EBCM replacement, setup, and programming