GM Service Manual Online
For 1990-2009 cars only

Circuit Description

When the electronic brake control module (EBCM) grounds the pump motor relay, it closes and provides battery voltage to the pump motor if the valve relay is closed. The EBCM senses the voltage applied to the pump motor to verify motor operation.

This DTC sets when the EBCM detects B+ without motor relay activation or if the EBCM does not detect B+ after motor relay activation.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0110 Pump Motor Circuit

Conditions for Running the DTC

    • Vehicle speed is greater than 6 km/h (4 mph) with the brake pedal not applied
        or
    • Vehicle speed is greater than 15 km/h (9 mph) and the brake pedal is actuated.

Conditions for Setting the DTC

    • There is a faulty terminal in the pump motor connector.
    • There is a faulty terminal in the EBCM connector.
    • There is a problem in the antilock brake system (ABS) wiring harness.
    • There is high resistance in the chassis ground.
    • The EBCM is defective.
    • There is a problem in the wiring from the pump motor connector to the motor.

Action Taken When the DTC Sets

The following actions occur:

    • The antilock brake system (ABS) is disabled.
    • The ABS warning indicator turns is ON.
    • The electronic brake force distribution (EBD) is disabled.

If the failure is intermittent, the EBCM will enable the system at the next ignition cycle and set a history DTC.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Diagnostic Aids

It is very important to perform a thorough inspection of the wiring and the connectors. Failure to do so may result in misdiagnosis, causing part replacement with reappearance of the malfunction.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step checks for connector damage.

  2. This step checks for an open or high resistance in the ground circuit.

  3. This step checks for a possible problem with the motor connector at the brake pressure modulator valve (BPMV).

Step

Action

Values

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. Disconnect the connector from the electronic brake control module (EBCM).
  2. Examine terminal 16 on the harness connector and on the EBCM connector.

Is the terminal damaged or corroded?

--

Go to Step 3

Go to Step 4

3

Repair or replace the terminal, the connector, the wiring harness, or the EBCM as required.

Did you complete the action?

--

Go to Step 9

--

4

Measure the resistance from terminal 16 of the harness connector to a good chassis ground.

Is the resistance equal to the specified value?

0 ohms

Go to Step 6

Go to Step 5

5

Repair the open or the high resistance in the harness between terminal 16 of the EBCM connector and ground.

Did you complete the repair?

--

Go to Step 9

--

6

  1. Remove the EBCM from the vehicle.
  2. Disconnect the EBCM connector and examine the terminals.

Is there any sign of damage or corrosion that would prevent a good ground contact?

--

Go to Step 7

Go to Step 8

7

Repair or replace the defective terminal, connector, or EBCM as required.

Did you complete the action?

--

Go to Step 9

--

8

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

Did you complete the replacement?

--

Go to Step 9

--

9

  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