GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The electronic brake control module (EBCM) performs several self-tests for internal problems, which may affect proper operation.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0550 Electronic Control Unit (ECU) Performance

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The EBCM detects an internal malfunction.

Action Taken When the DTC Sets

    • The EBCM disables the ABS/dynamic rear proportion (DRP)/traction control system (TCS)/vehicle stability enhancement system (VSES).
    • The ABS indicator turns ON.
    • The brake warning indicator turns ON.
    • The message center displays the service stability system message.
    • The traction OFF indicator turns ON.

Conditions for Clearing the DTC

Certain conditions that may cause this DTC to set cannot be cleared. Other conditions that may cause this DTC to set may be cleared, at least temporarily, by using the scan tool Clear DTCs function.

Diagnostic Aids

Replace the EBCM if this DTC continues to set intermittently.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Use a scan tool in order to clear the DTCs.

Can the DTC be cleared?

Go to Step 3

Go to Step 4

3

  1. Turn OFF the ignition.
  2. Turn ON the ignition.

Does the DTC reset?

Go to Step 4

Go to Diagnostic Aids

4

Replace the electronic brake control module (EBCM). Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 5

--

5

  1. Use the scan tool to clear the DTCs.
  2. Turn OFF the ignition for 5 seconds.
  3. Turn ON the ignition.
  4. 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