GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The system relays are energized when the ignition is ON and the vehicle speed is greater than 6 km/h (4 mph). The system relay supplies voltage to the solenoid valves and to the pump motor. This voltage is referred to as the system voltage. The EBCM controls the solenoid valves by grounding the control circuit.

Conditions for Running the DTC

    • The ignition is ON.
    • The vehicle speed is greater than 6 km/h (4 mph).

Conditions for Setting the DTC

The EBCM detects an internal malfunction.

Action Taken When the DTC Sets

C0241, C0242, C0245, C0246, C0251, C0252, C0253, C0254

If equipped, the following actions occur:

    • The EBCM disables the DRP/ABS.
    • The ABS indicator turns ON.
    • The red Brake warning indicator turns ON.
    • The DIC displays the SERVICE BRAKE SYSTEM message.

C0243, C0244, C0247, C0248

If equipped, the following actions occur:

    • The EBCM disables the ABS.
    • The ABS indicator turns ON.
    • The DIC displays the SERVICE BRAKE SYSTEM message.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

An intermittent open/shorted solenoid DTC can be set by several different internal EBCM problems. Replace the EBCM if an open/shorted solenoid DTC continues to set intermittently.

Step

Action

Yes

No

1

Did you perform the ABS Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Use a 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 set?

Go to Step 3

Go to Diagnostic Aids

3

Important: Following EBCM replacement, use the scan tool to perform the Tire Size Calibration procedure and the Trim Level Calibration procedure, if applicable.

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