GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The electronic brake control module (EBCM) supplies ground to activate the antilock brake system (ABS) pump motor. An internal system relay in the EBCM supplies battery positive voltage to the pump motor when the ignition is turned ON. The EBCM monitors pump motor feedback voltage after activation to detect a stalled or binding pump motor.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC C0111 Pump Motor Circuit Range/Performance
    • DTC C0113 Pump Motor Circuit High
    • DTC C0114 Pump Motor Circuit Open
    • DTC C0115 Pump Motor Performance
    • DTC C0120 Pump Motor Relay Circuit Open

Conditions for Running the DTC

C0111

    • The ignition voltage is greater than 8 volts.
    • The pump motor has been commanded OFF for longer than 1.4 seconds and then commanded ON.
    • Voltage to the pump motor is greater than 11 volts when the pump motor is commanded ON.

C0113

    • The ignition voltage is between 9.2-17 volts.
    • The system enable relay is ON.

C0114

    • The system voltage is between 10.1-17 volts.
    • The ignition voltage is between 9.2-17 volts.
    • The system enable relay is ON.
    • The pump motor has been commanded OFF for 1.4 seconds.

C0115

    • The system and ignition voltage is greater than 8 volts.
    • The system enable relay is ON.
    • The pump motor is commanded ON.
    • No other pump motor faults have been detected

C0120

    • The system and ignition voltage is greater than 8 volts.
    • The system enable relay is ON.
    • The pump motor is commanded ON.

Conditions for Setting the DTC

C0111

The EBCM excessive current draw from the pump motor.

C0113

The EBCM detects an open in the pump motor ground circuit.

C0114

This code sets for a possible open in the pump motor.

C0115

The EBCM monitors pump motor feedback voltage after activation.

C0120

This code sets for a possible open in the internal EBCM pump motor relay circuit.

Action Taken When the DTC Sets

If equipped, the following actions occur:

    • The EBCM disables the ABS/traction control system (TCS)/vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
    • The dynamic rear proportion (DRP) is degraded.
    • The ABS indicator turns ON.
    • The stability OFF 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 EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

The pump motor is integral to the brake pressure modulator valve (BPMV). The pump motor is not serviceable.

Test Description

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

  1. This step tests the ability of the EBCM to control the pump motor. If the test lamp illuminates, the pump motor circuit within the EBCM is good.

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

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 OFF the engine.

Does the DTC reset?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

  1. Remove the electronic brake control module (EBCM) from the brake pressure modulator valve (BPMV). Refer to Electronic Brake Control Module Replacement .
  2. Inspect the EBCM to BPMV connector for conditions which could cause an intermittent, such as damage, corrosion, poor terminal contact, or presence of brake fluid.

Is the connector OK and the cavity free of brake fluid?

Go to Step 5

Go to Step 4

4

  1. If connector corrosion or damage is evident, replace BPMV and/or EBCM as necessary.
  2. If brake fluid is present, replace both BPMV and EBCM. Refer to Brake Pressure Modulator Valve Replacement and Control Module References for replacement, setup, and programming.

Did you complete the repair?

Go to Step 8

--

5

  1. Connect the EBCM harness to the EBCM with the BPMV still separated.
  2. Connect a test lamp between the pump motor circuits, internal EBCM side, using the J 35616 GM Terminal Test Kit .
  3. Cycle the ignition to the OFF position.
  4. Start the engine.
  5. In PARK or NEUTRAL, release the brake.

Does the test lamp illuminate and then turn OFF?

Go to Step 7

Go to Step 6

6

Replace the EBCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the repair?

Go to Step 8

--

7

Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement .

Did you complete the repair?

Go to Step 8

--

8

  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 2

System OK