GM Service Manual Online
For 1990-2009 cars only

Object Number: 396362  Size: MF
ABS Components
Cell 44: ABS Pump Motor, BPMV, Solenoid Valves, and Stoplamp Switch
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 Setting the DTC

    • The Electronic Brake Control Module (EBCM) detects an open in the pump motor circuitry.
    • DTC C0116 can be set anytime.

Action Taken When the DTC Sets

    • A malfunction DTC stores
    • 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 number(s) below refer to the step number(s) on the diagnostic table.

  1. If the pump motor relay is stuck in the ON position, the pump motor will run all the time regardless of ignition switch position until the battery is dead.

  2. Tests the pump motor by turning it ON and OFF through the scan tool. The scan tool will display if the EBCM commands the pump motor ON and the feedback status.

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

Turn the ignition switch to the LOCK position.

Is the BPMV pump motor still running?

--

Go to Step 5

Go to Step 3

3

  1. Connect a scan tool to the OBD2 Data Link Connector (DLC).
  2. Turn the ignition switch to the ON position.
  3. Select Diagnostic Trouble Codes (DTCs) on the scan tool.
  4. Select Clear DTC Information on the scan tool.
  5. Select Special Functions from the Application Menu on the scan tool.
  6. Select Device Control on the scan tool.
  7. Command the pump motor ON.

Did the scan tool display pump motor command ON and monitor ON during this test?

--

Go to Step 6

Go to Step 4

4

  1. Disconnect the EBCM electrical connector.
  2. Using J 39200 (DMM), measure the resistance between the EBCM electrical connector terminal C (harness side) and ground.

Is the resistance within the specified range?

0-2 ohms

Go to Step 5

Go to Step 7

5

Replace the Brake Pressure Modulator Valve (BPMV) assembly. Refer to Brake Pressure Modulator Valve Assembly Replacement .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

6

A malfunction is not present at this time. Refer to Diagnostic Aids for additional information regarding this DTC.

Is the action complete?

--

Go to Diagnostic System Check - ABS

--

7

Repair the open or high resistance in the WHT/BLK wire between the EBCM terminal C and ground. Clean and tighten G103.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--