GM Service Manual Online
For 1990-2009 cars only

Object Number: 412173  Size: MF
ABS Components
Brake Pressure Modulator Valve (BPMV)

Circuit Description

The electronic brake control relay supplies power to the solenoid valves and pump motor. The relay activates when the ignition is turned ON. Power is available to the solenoid valves and pump motor through the relay via the battery supply circuit. The relay remains engaged until you turn OFF the ignition.

Conditions for Running the DTC

    • The ignition voltage is greater than 10.5 volts.
    • The system relay is commanded ON.

Conditions for Setting the DTC

DTC C1214 will set anytime the solenoid valve relay is commanded ON and the relay voltage is less than 8 volts, and ignition voltage is greater than 10.5 volts.

Action Taken When the DTC Sets

    • ABS is disabled.
    • 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.
    • 100 drive cycles pass with no DTC(s) detected. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition OFF.

Diagnostic Aids

Possible Causes:

    • Weak or discharged battery
    • Loose or corroded battery terminals
    • Loose or corroded engine grounds
    • Poor terminal contact at the EBCM

It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.

If an intermittent malfunction exists refer to General Electrical Diagnosis in Wiring Systems.

The relay is integral to the EBCM and is not serviceable separately.

Test Description

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

  1. This step determines whether the DTC is current.

Step

Action

Value(s)

Yes

No

1

Did you perform the ABS Diagnostic System Check?

--

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. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset as a current DTC?

--

Go to Step 3

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

3

Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Did you complete the repair?

--

Go to Step 4

--

4

  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