GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This DTC is used to detect a sudden loss of voltage or ground to the electronic brake control module (EBCM). Battery voltage is applied to terminals 1 and 2. Switched ignition voltage is applied to terminal 13.

Ground is supplied to terminal 14 and 15.

Conditions for Setting the DTC

C0054 will set when the EBCM has detected that power or ground had been lost and then regained within a short period of time.

Action Taken When the DTC Sets

    • The solenoid relay opens, removing power from the pump motor and solenoids.
    • DTC C0054 is stored
    • ABS disabled, ABS warning lamp turns ON.
    • DDRP disabled, brake warning lamp turns ON.

Conditions for Clearing the DTC

    • If the conditions that set DTC C0054 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

Typical causes for DTC C0054:

    • Weak or discharged battery
    • Loose or poor battery terminals
    • Battery disconnected
    • Loose or poor ground cables
    • Poor EBCM terminal contact
    • Excessive parasitic draws
    • Charging system malfunction

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check-ABS?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Load test the battery.
  2. Inspect the charging system
  3. Perform a parasitic load test.

Did the battery, charging system, and parasitic load test pass?

--

Go to Step 4

Go to Step 3

3

  1. Repair the charging system.
  2. If necessary, recharge the battery.
  3. If necessary, replace the battery. Refer to Battery and Battery Tray Replacement in Engine Electrical.
  4. Find the source of the excessive parasitic draw.
  5. Repair the source of the excessive parasitic draw.

Did you find and correct the condition?

--

System OK

--

4

  1. Turn the ignition switch OFF.
  2. Disconnect the battery positive and negative terminals.
  3. Disconnect the harness from the EBCM.
  4. Inspect the following for a poor connection:
  5. • Battery terminal cables
    • Negative cable to block and/or chassis
    • Positive cable to starter solenoid and/or junction block
    • EBCM terminals 1, 2, 13, 21
    • EBCM ground wire to chassis ground.

Were all the above connections satisfactory?

--

Go to Step 6

Go to Step 5

5

Repair the terminal and/or connections as needed.

Did you find and correct the condition?

--

System OK

--

6

  1. The EBCM is still disconnected.
  2. The battery cables are still disconnected.
  3. Connect an ohmmeter to terminal 13 of the EBCM harness and the negative battery cable.

Was the resistance measured less than the specified value?

2 ohms

Go to Step 8

Go to Step 7

7

  1. Find the source of high resistance between the negative battery cable and the EBCM harness connector.
  2. Repair the source of high resistance between the negative battery cable and the EBCM harness connector.

Did you find and correct the condition?

--

System OK

--

8

  1. Reconnect the battery cables.
  2. The EBCM is still disconnected.
  3. Turn ON the ignition, with the engine OFF.
  4. Using a voltmeter, measure the voltage on the EBCM harness terminals 1, 2, 13.

Was the voltage on all 3 terminals above the specified value?

B+

Go to Step 10

Go to Step 9

9

  1. Find the source of low voltage to the EBCM terminals.
  2. Repair the source of low voltage to the EBCM terminals.

Did you find and correct the condition?

--

System OK

--

10

Replace the EBCM. Refer to Brake Pressure Modulator Valve Assembly Replacement .

Did you complete the replacement?

--

System OK

--