GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The electronic brake control module (EBCM) proceeds the self-test about the dump valve or the motor driver, if the EBCM senses the brake signal.

Conditions for Running the DTC

If the EBCM proceeds the self-test about the dump valve or the motor driver and senses the fault, the EBCM may make the fault code.

Conditions for Setting the DTC

EBCM internal fault -- Left rear dump voltage shorted or ground open

Action Taken When the DTC Sets

    • Antilock brake system (ABS) warning lamp ON
    • ABS warning lamp OFF if the ignition switch ON/OFF

This is a critical operational fault. The ABS is disabled and the ABS warning lamp is turned ON. The proportioning is operation.

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

  1. Turn the ignition switch to OFF.
  2. Remove the fuse Ef1 in the engine fuse block.
  3. Check for an open in fuse Ef1.

Is the fuse open?

--

Go to Step 3

Go to Step 2

2

Replace the fuse Ef1.

Is the repair complete?

--

System OK

--

3

  1. Disconnect the EBCM harness connector.
  2. Turn the ignition switch to ON.
  3. Use a digital voltmeter (DVM) to measure the voltage between ground and terminal 18 of the EBCM connector.

Is the voltage within the specified value?

10.5-13.5 V

Go to Step 5

Go to Step 4

4

Repair the short to voltage between terminal 18 of the EBCM connector and engine fuse block Ef1 output.

Is the repair complete?

--

System OK

--

5

Use a DVM to measure the voltage between terminal 18 and terminal 19 of the EBCM connector.

Is the voltage within the specified value?

10.5-13.5 V

Go to Step 7

Go to Step 6

6

Repair the open between terminal 19 of the EBCM connector and ground G101.

Is the repair complete?

--

System OK

--

7

Replace the EBCM.

Is the repair complete?

--

System OK

--