GM Service Manual Online
For 1990-2009 cars only

Object Number: 490148  Size: LF
Antilock Brake System Component Views
Antilock Brake System Schematics
Power Distribution Schematics
Power Distribution Schematics
Power Distribution Schematics
Handling Electrostatic Discharge Sensitive Parts Notice

Circuit Description

The electronic brake control relay supplies voltage to the solenoid valves and pump motor when energized. This voltage is refereed to as the system voltage. The electronic brake control relay, located in the EBCM, is activated whenever the ignition switch is in the RUN position and no faults are present. The electronic brake control relay remains energized until the ignition switch is turned off or when ABS is disabled.

Conditions for Running the DTC

    • The ignition voltage is greater than 10.8 volts.
    • The electronic brake control relay is commanded ON.

Conditions for Setting the DTC

    • The system voltage is less than 8 volts.
    • The above conditions are present for greater than 0.23 seconds.

Action Taken When the DTC Sets

If equipped, the following actions occur:

    • The EBCM disables the ABS/TCS for the duration of the ignition cycle.
    • The ABS indicator turns ON.
    • The Traction Off indicator turns ON.
    • The message center displays the Service Traction System message.

Conditions for Clearing the DTC

    • Condition for DTC is no longer present and scan tool clear DTC function is used.
    • 100 ignition cycles have passed with no DTCs detected.

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

Schematic Reference: Antilock Brake System Schematics

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. With the scan tool, perform the Automated Test.

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. With the scan tool, perform the Automated Test.

Does the DTC reset?

--

Go to Step 2

System OK