For 1990-2009 cars

### Circuit Description

Ground is continuously supplied to the low side of the Antilock Brake System (ABS) pump motor. The electronic brake control module (EBCM) activates the ABS pump by supplying adequate current 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 EBCM has commanded the pump motor ON at least once during the current ignition cycle.

### 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.

• | The ABS indicator turns ON.

• | The ABS fault message is displayed.

• | An ECE 13 response occurs. 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 connectors. Refer to Control Module References and Testing for Intermittent Conditions and Poor Connections . If severe corrosion or other damage exists, the BPMV or the EBCM may need to be replaced.

Inspect for poor connections that may affect the battery positive voltage circuit to terminal 4 or the ground circuit to terminal 3 of the EBCM harness connector, if this DTC continues to set intermittently. Replace the EBCM, if no wiring concerns are found.

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 a scan tool in order to clear the DTCs.
2. Select the Antilock Brake System (ABS) Special Functions menu on the scan tool.
3. Select ABS Motor.
4. Use the scan tool to command the ABS Motor On and then Off.
5. Press the Exit key on the scan tool.

Does the DTC reset?

Go to Step 3

Go to Diagnostic Aids

3 |

1. Turn OFF the ignition.
2. Disconnect the electronic brake control module (EBCM) harness connector.
3. Connect a test lamp between the battery positive voltage circuit at terminal 4 of the EBCM harness connector and a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 4

4 | Repair the open in the battery positive voltage circuit. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 12 | --
5 | Connect a test lamp between the battery positive voltage circuit at terminal 4 of the EBCM harness connector and the ground circuit at terminal 3 of the EBCM harness connector. Does the test lamp illuminate? | Go to Step 7 | Go to Step 6
6 | Repair the open in the motor ground circuit. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 12 | --
7 |

1. Separate the EBCM from the brake pressure modulator valve (BPMV). Refer to Control Module References .
2. Inspect for poor connections at the pump motor connectors. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 8

8 | Important: The test lamp must remain properly connected to the pump motor terminals whenever the ignition is ON, or incorrect test results may be obtained.

1. Connect a test lamp between the 2 pump motor connectors on the EBCM.
2. Turn ON the ignition.
3. Select the ABS Special Functions menu on the scan tool.
4. Select ABS Motor.
5. Use the scan tool to command the ABS Motor On and then Off.

Does the test lamp illuminate and then turn Off with each command?

Go to Step 9

Go to Step 11

9 | Press the Exit key on the scan tool. Does the DTC reset? | Go to Step 11 | Go to Step 10
10 | Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Did you complete the replacement? | Go to Step 12 | --
11 | Replace the EBCM and the BPMV. Refer to Control Module References for replacement, setup, and programming and Brake Pressure Modulator Valve Replacement . Did you complete the replacements? | Go to Step 12 | --
12 |

1. Use a 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 3

System OK