GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2006 🢒 GTO 🢒 DTC 🢒 DTC C0800

Circuit Description

The electronic brake control module (EBCM) monitors the battery supply voltage available to the EBCM.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0800 System Voltage Low, System Voltage High, or System Voltage Performance

Conditions for Running the DTC

DTC C0800 can be set anytime the ignition switch is in the ON position.

Conditions for Setting the DTC

Vehicle speed is above 6 km/h (4 mph) and one of the following occurs:

    • EBCM battery supply voltage drops below 9.4 volts and the ABS/TCS is not active
    • EBCM battery supply voltage drops below 8.8 volts and the ABS/TCS is active
    • EBCM battery supply voltage exceeds 17.4 volts

Action Taken When the DTC Sets
    • The EBCM disables the antilock brake and traction control systems for the duration of the ignition cycle.
    • The ABS, TRAC OFF and BRAKE warning indicators turn 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.

Diagnostic Aids

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

    • A charging system malfunction
    • An open, high resistance or short to ground in the EBCM battery supply voltage circuits
    • An open or high resistance in the EBCM ground circuit
    • An internal EBCM malfunction

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

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

  1. This step tests the charging system.

    2.

  2. This step tests the battery supply voltage circuit for an open, high resistance or short to ground.

    3.

  3. This step tests the EBCM ground circuit for an open or high resistance.

Step

Action

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?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Test the charging system. Refer to Charging System Test

Did you find and correct the condition?

Go to Step 8

Go to Step 3

3
  1. Install a scan tool.
  2. Use the scan tool in order to clear the DTCs.
  3. Turn ON the ignition, with the engine running.
  4. Operate the vehicle within the Condition for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 4

Go to Diagnostic Aids

4

Test the electronic brake control module (EBCM) battery supply voltage circuits for an open, high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 8

Go to Step 5

5

Test the EBCM ground circuit for an open, or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 8

Go to Step 6

6

Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 8

Go to Step 7

7

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

Did you complete the replacement?

Go to Step 8

--

8
  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