GM Service Manual Online
For 1990-2009 cars only

Object Number: 524886  Size: MF
ABS Components
Antilock Brake System Schematics
Handling ESD Sensitive Parts Notice
Power Distribution Schematics
Power Distribution Schematics

Circuit Description

The pump motor is an integral part of the Brake Pressure Modulator Valve (BPMV). The EBCM relay supplies power to the solenoid valves and pump motor. The EBCM relay activates when the ignition is turned to the ON position. The EBCM relay remains engaged until the ignition is turned to the OFF position or until the system detects a malfunction.

Conditions for Running the DTC

    • The pump motor has been commanded OFF for 1 second.
    • The switched system battery voltage is greater than 9 volts.

Conditions for Setting the DTC

One of the following conditions occur:

    • Voltage across the pump motor is greater than 10.16 volts for 0.2 seconds.
    • The pump motor low side voltage is less than 2.7 volts for 0.2 seconds.

Action Taken When the DTC Sets

The following actions occur:

    • The EBCM disables the ABS for the duration of the ignition cycle.
    • The ABS warning indicator turns ON.
    • A malfunction DTC is stored.

Conditions for Clearing the DTC

    • The condition for setting the DTC is no longer present and the scan tool Clear DTCs function is used.
    • The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

    • Possible causes for DTC C1217 to set are:
       - The Pump motor is shorted to ground.
       - An internal EBCM malfunction exists.
    • The pump motor is an integral part of the BPMV and is not serviced separately.
    • The EBCM relay is an integral part of the EBCM and is not serviced separately.
    • It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect the wiring and connectors may result in a misdiagnosis, causing part replacement with a reappearance of the malfunction.
    • If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

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

  1. This step tests the pump motor circuits of the BPMV for a short to the housing of the BPMV.

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. Turn OFF the ignition.
  2. Disconnect the EBCM harness connector
  3. Connect the J 39700 universal pinout box using the J 39700-99 cable adapter to the EBCM harness connector only.
  4. Test both ground circuits of the EBCM including ground G112 for a high resistance or an open.

Did you find and correct the condition?

--

Go to Step 6

Go to Step 3

3

  1. Remove the EBCM. Refer to Electronic Brake Control Module Replacement .
  2. Measure the resistance from both pump motor control circuits of the BPMV to the housing of the BPMV.

Does the resistance measure less than the specified value?

OL (Infinite)

Go to Step 4

Go to Step 5

4

Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement .

Did you complete the repair?

--

Go to Step 6

--

5

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

Did you complete the repair?

--

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