GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2004 🢒 XLR 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 DTC C0220-C0229

Circuit 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.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC C0220 Left Front ABS Channel in Release Too Long
    • DTC C0221 Right Front ABS Channel in Release Too Long
    • DTC C0228 Left Rear ABS Channel in Release Too Long
    • DTC C0229 Right Rear ABS Channel in Release Too Long

Conditions for Running the DTC
    • The ignition is ON.
    • The vehicle is experiencing an ABS event.

Conditions for Setting the DTC

This code is set when the following criteria are met.

    • The EBCM is commanding a valve solenoid to release brake pressure.
    • The wheel that is commanded to release brake pressure has a speed below 5 km/h (3 mph) for 1.25 seconds.

Action Taken When the DTC Sets

If equipped, the following actions occur.

    • The EBCM disables ABS/TCS.
    • ACC Braking is degraded.
    • VSES is disabled.
    • The ABS indicator turns ON.
    • The traction off indicator turns ON.

Conditions for Clearing the DTC
    • The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
    • The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

The solenoid valve circuit is internal to the EBCM. The solenoid valve circuit is not diagnosable external to the EBCM. The DTC sets when there is a malfunction in the solenoid circuit internal to the EBCM.

Possible causes for this concern:

    • Intermittent wheel speed sensor
    • Wheel speed sensor is equal to 0 km/h (0 mph)
    • Contaminated hydraulic unit

Test Description

The number below refers to the step number on the diagnostic table.

  1. Determines whether the DTC is current.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Use the scan tool in order to clear the DTCs.
  2. Cycle the ignition to the OFF position.
  3. Start the engine.
  4. In park or neutral, release the brake.
  5. Turn the engine OFF.

Does the DTC reset?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3

Important: Perform the setup procedure for the EBCM. An unprogrammed EBCM will result in the following conditions:

   • Inoperative or poorly functioning system operations
   • The EBCM may set DTCs

Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Did you complete the replacement?

Go to Step 4

--

4
  1. Use the scan tool in order to clear the DTCs
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 3

System OK