GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The electronic brake control module (EBCM) monitors the voltage level available for system operation. A low voltage condition prevents the system from operating properly.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0899 Device Voltage Low

Conditions for Running the DTC

The system relay is commanded ON.

Conditions for Setting the DTC

One of the following conditions exists for 0.72 second:

    • During initialization or when the system is inactive, the system voltage is less than 10.5 volts.
    • During the system operation, the system voltage is less than 9 volts.

Action Taken When the DTC Sets

    • The EBCM disables the ABS and dynamic rear proportion (DRP) is degraded when the code is current.
    • The ABS indicator turns ON.

Conditions for Clearing the DTC

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

Diagnostic Aids

    • Test the charging system. Refer to Diagnostic System Check - Vehicle in Vehicle DTC Information.
    • Possible causes of this DTC are the following conditions:
       - A charging system malfunction
       - An excessive battery draw
       - A weak battery
       - A faulty system ground

Test Description

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

  1. Use the scan tool in order to inspect the voltage to the EBCM.

  2. This step verifies that the condition is still present.

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Start the engine.
  3. With a scan tool, observe the Switched Battery Voltage Signal parameter in the ABS data list.

Does the scan tool indicate the voltage is greater than the specified value?

10.5 V

Go to Diagnostic Aids

Go to Step 3

3

With a scan tool, observe the Ignition Voltage Signal parameter in the ABS data list.

Does the scan tool indicate the voltage is greater than the specified value?

10.5 V

Go to Step 4

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

4

Test the ground circuits of the electronic brake control module (EBCM) including the EBCM ground for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 5

5

  1. Connect the EBCM harness connector.
  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?

--

Go to Step 6

Go to Diagnostic Aids

6

Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the repair?

--

Go to Step 7

--

7

  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