GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 GTO 🢒 DTC 🢒 DTC 71

Circuit Description

This DTC identifies a malfunction within the electronic brake control module (EBCM).

Conditions for Running the DTC

DTC 71 can be set anytime the ignition switch is in the ON position.

Conditions for Setting the DTC

The EBCM fails self diagnostic check.

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 and TRAC OFF 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:

    • An open, high resistance or short to ground in the EBCM ignition positive voltage 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 step numbers on the diagnostic table.

  1. This step tests the ignition positive voltage circuit of the EBCM for an open, high resistance or short to ground.

Step

Action

Value(s)

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform A Diagnostic System Check - ABS?

--

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 read the chassis DTCs.

Are there any additional DTCs?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3
  1. Use the scan tool in order to clear the DTCs.
  2. Road test the vehicle.

Does DTC 71 set?

--

Go to Step 3

Go to Diagnostic Aids

4
  1. Disconnect the electronic brake control module (EBCM) harness connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage of the EBCM ignition voltage circuit. Refer to Circuit Testing in Wiring Systems.

Does the voltage measure as specified?

At least 10 V

Go to Step 5

Go to Step 6

5

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

Did you find and correct the condition?

--

Go to Step 10

Go to Step 7

6

Test the EBCM ignition positive voltage circuit for an open, high resistance or short to ground. Refer to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 8

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 9

System OK

8

Locate and repair the open, high resistance or short to ground in the ignition control relay circuits. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

--

9

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

Did you complete the replacement?

--

Go to Step 10

--

10
  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