For 1990-2009 cars
ABS Components
Antilock Brake System Schematics
Handling ESD Sensitive Parts Notice

### Circuit Description

The pump motor relay is part of the Electronic Brake Control Module (EBCM). The EBCM turns ON and OFF the pump motor relay as deemed necessary in order to activate the pump motor. The pump motor modulates brake hydraulic pressure during an ABS stop.

### Conditions for Running the DTC

DTC C0116 can be set anytime the ignition switch is in the ON position.

### Conditions for Setting the DTC

The Electronic Brake Control Module (EBCM) detects an open in the pump motor circuitry.

### Action Taken When the DTC Sets

• | The ABS disables

• | The ABS warning indicator turns ON

### Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used. Although, after the scan tool erases DTC C0116, the EBCM keeps the ABS indicator ON until the vehicle is driven 10 mph for at least 20 seconds AND the pump motor sends a proper monitor signal to the EBCM. Then the EBCM turns OFF the ABS indicator. If the pump motor monitor signal is still incorrect, DTC C0116 will set again as a current DTC and the ABS indicator remains ON.

### Diagnostic Aids

Inspect the ABS fuse when diagnosing this part of the Antilock Brake System (ABS)

Inspect the harness connectors for the following conditions:

• | Backed-out terminals

• | Improper mating

• | Broken locks

• | Improperly formed or damaged terminals

• | Poor terminal to wiring connections or physical damage to the wiring harness

### Test Description

The numbers below refer to step numbers on the Diagnostic Table.

1. This step determines whether the DTC is current.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform A Diagnostic System Check - ABS? | -- | Go to Step 2 | Go to Diagnostic System Check - ABS
2 |

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Use the scan tool in order to clear the DTCs.
4. Using the scan tool, cycle the pump motor in the Special Functions menu.
5. Read the DTCs.

Does the DTC reset?

--

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3 |

1. Test the Pump Motor Input circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. Test the Motor Ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Was a problem found and corrected?

--

Go to Diagnostic System Check - ABS

Go to Step 4

4 | Replace the Brake Modulator Assembly. Refer to Brake Pressure Modulator Valve Assembly Replacement . Is the repair complete? | -- | Go to Step 5 | --
5 |

1. Use the scan tool in order to clear the DTCs.
2. Using the scan tool, cycle the pump motor in the Special Functions menu.
3. Read the DTCs.

Does the DTC reset?

--

Go to Step 2

System OK