GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This DTC identifies a possible malfunction within the electronic brake control module (EBCM). When the EBCM relay is activated, voltages are supplied to the valve solenoids and pump motor.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C2112 Solenoid Valve Relay Circuit

Conditions for Running the DTC

Ignition is in the ON position.

Conditions for Setting the DTC

DTC C2112 will set when a possible internal malfunctions exist.

Action Taken When the DTC Sets

    • ABS warning lamp is not turned ON.
    • DTC C2112 is stored.
    • ABS remains functional.

Conditions for Clearing the DTC

    • If the conditions that set DTC C2112 are no longer present, the DTC may be cleared by using the proper scan tool.
    • The DTC that has not occurred in 100 drive cycles will be cleared from the history data.

Diagnostic Aids

    • Repair low voltage, driveability, or other electrical complaints first, prior to performing DTC C2112.
    • Ensure the integrity of the connection between the EBCM and the brake pressure modulator valve (BPMV) is secure, tight, and free of corrosion, leaks, and/or damage.
    • Possible cause for DTC C2112 to set is an internal relay problem within the EBCM.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install the scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Using the scan tool, observe the DTC information.

Does the scan tool display any DTCs set in current or history data other than DTC C2112?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 3

3

  1. Turn the ignition switch OFF.
  2. Disconnect the harness from the electronic brake control module (EBCM).
  3. Check the resistance between terminal 25 of the wiring harness connector and ground.

Was the resistance as specified?

0 ohms

Go to Step 5

Go to Step 4

4

  1. Check the fuse Ef4 from the engine room fuse block.
  2. Check the connectors for damage, corrosion, and terminal contact, including terminal 25.
  3. Repair as needed.

Did you find and correct the condition?

--

Go to Step 6

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5

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

Did you complete the replacement?

--

Go to Step 6

--

6

  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