GM Service Manual Online
For 1990-2009 cars only

Circuit Description

Ground is continuously supplied to the low side of the ABS pump motor. The electronic brake control module (EBCM) activates the ABS pump by supplying battery voltage to the high side of the motor.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0110 Pump Motor Circuit

Conditions for Running the DTC

    • The ignition is ON.
    • The vehicle speed is greater than 6 km/h (4 mph).

Conditions for Setting the DTC

The EBCM detects an open pump motor circuit, a shorted pump motor, or a seized pump motor or ABS pump.

Action Taken When the DTC Sets

    • The EBCM disables the ABS/vehicle stability enhancement system (VSES).
    • The traction control system (TCS) operates with engine torque reduction ability only.
    • The ABS indicator turns ON.
    • The stability indicator turns ON.
    • An ECE 13 response may occur. Refer to ABS Description and Operation for a complete description of ECE 13.

Conditions for Clearing the DTC

The Conditions for Setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

Separate the EBCM from the brake pressure modulator valve (BPMV) in order to inspect for corrosion or any other condition that may cause a poor connection at the pump motor connector. Refer to Electronic Brake Control Module Replacement and Testing for Intermittent Conditions and Poor Connections in Wiring Systems. If severe corrosion or other damage exists, the BPMV or the EBCM may need to be replaced.

Test Description

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

  1. This step tests for high resistance in the battery positive voltage circuit by verifying that an excessive voltage drop does not occur in the circuit.

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 in Vehicle DTC Information

2

  1. Use a scan tool to clear the DTCs.
  2. Turn OFF the ignition for 5 seconds.
  3. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC set?

--

Go to Step 3

Go to Diagnostic Aids

3

  1. Disconnect the electronic brake control module (EBCM) harness connector.
  2. Connect a test lamp between the battery positive voltage circuit to the ABS pump motor, and a good ground.

Does the test lamp illuminate?

--

Go to Step 4

Go to Step 5

4

Important: Using a test lamp other than that which is approved for performing diagnostic procedures on GM vehicles, may cause an inaccurate result when performing this step. It is also imperative that the ground to which the test lamp is connected be clean and provide no resistance to battery ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems for more information.

With the test lamp still connected and illuminated, use a DMM to measure the voltage between the high side of the test lamp and a good ground.

Does the voltage measure greater than the specified value?

12 V

Go to Step 6

Go to Step 5

5

Repair the high resistance in the battery positive voltage circuit. Ensure that total circuit resistance is not greater than the specified value. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

0.2 ohms

Go to Step 13

--

6

Test the ABS motor ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 7

7

  1. Turn OFF the ignition.
  2. Separate the EBCM from the brake pressure modulator valve (BPMV). Refer to Control Module References in Computer/Integrating Systems.
  3. Connect a test lamp between the ABS pump motor power and ground circuits at the pump motor connector of the EBCM.
  4. Turn ON the ignition.
  5. Use the scan tool in order to clear the DTCs.

Does the DTC clear and then remain cleared while the test lamp is connected?

--

Go to Step 8

Go to Step 10

8

  1. Select the vehicle stability enhancement system (VSES) Special Functions menu on the scan tool.
  2. Command the ABS Motor ON.

Does the test lamp illuminate for 5 seconds and then turn OFF?

--

Go to Step 9

Go to Step 12

9

Inspect for poor connections at the pump motor connector.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 11

10

Important: Following the EBCM replacement, perform the set-up procedure for the EBCM and perform the Yaw Rate Reference Table Reset Procedure. Use the scan tool to perform the Tire Size Calibration procedure.

Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems.

Did you complete the replacement?

--

Go to Step 13

--

11

Replace the BPMV. Refer to Control Module References in Computer/Integrating Systems.

Did you complete the replacement?

--

Go to Step 13

--

12

Important: Following EBCM replacement, perform the set-up procedure for the EBCM and perform the Yaw Rate Reference Table Reset Procedure. Use the scan tool to perform the Tire Size Calibration procedure.

Replace the EBCM and the BPMV. Refer to Control Module References in Computer/Integrating Systems.

Did you complete the replacements?

--

Go to Step 13

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13

  1. Use the scan tool Clear All Class 2 DTCs function to clear all of the DTCs from all modules.
  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