GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This DTC identifies a possible malfunction within the electronic brake control module (EBCM).

Conditions for Setting the DTC

DTC C0055 will set when a possible internal component/microprocessor problem may exist.

Action Taken When the DTC Sets

The solenoid relay opens, removing power from the pump motor and the solenoids.

The ABS and DDRP are Disabled

    • DTC C0055 is stored.
    • The antilock brake system (ABS) warning lamp and brake warning lamp are turned ON.

Conditions for Clearing the DTC

    • If the conditions that set DTC C0055 are no longer present, the DTC may be cleared by using the proper scan tool.
    • The DTC that has not occurred in 100 drive cycles will be cleared from history data.

Diagnostic Aids

    • When DTC C0055 is displayed on the scan tool, it should be followed by 2 additional numbers, xx, which should be documented along with any other DTCs that may be displayed.
    • Repair low voltage, driveability, or other electrical complaints first, prior to performing DTC C0055.
    • Make sure the integrity of the connection between the EBCM and the brake pressure modulator valve (BPMV) is secure, tight, and free of corrosion, leaks, and/or damage.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check-ABS?

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Install the scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. Using the scan tool, observe DTC information.

Do any DTCs set in Current or History Data other than C0055 XX?

Go to Step 3

Go to Step 4

3

Perform the applicable DTC diagnostic for the other DTCs.

Did you find and correct the condition?

System OK

--

4

  1. Turn the ignition switch OFF.
  2. Disconnect the harness from the electronic brake control module (EBCM).
  3. Check the connectors for damage, corrosion, and terminal contact.

Were any problems found?

Go to Step 5

Go to Step 6

5

Repair as needed.

Did you find and correct the condition?

System OK

--

6

Replace the EBCM.

Did you complete the replacement?

System OK

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