GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The electronic brake control module (EBCM) supplies approximately 12 volts through an internal resistor to the powertrain control module (PCM) on the delivered torque signal circuit. The PCM toggles this voltage to ground in order to create a valid delivered torque signal at the EBCM.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC C0244 Pulse Width Modulated (PWM) Delivered Torque
    • DTC P1689 Traction Control Delivered Torque Output Circuit

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The EBCM receives an invalid delivered torque signal for 1 second.

Action Taken When the DTC Sets

    • The EBCM disables the traction control switch (TCS).
    • The traction fault message is displayed.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to Testing for Electrical Intermittents , Testing for Intermittent Conditions and Poor Connections , Connector Repairs , and Wiring Repairs .

Test Description

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

  1. This step tests for voltage supplied to the PCM from the EBCM.

  2. This step tests for a shorted resistor in the EBCM or a short to voltage within the circuit, by verifying that a large voltage drop occurs in the circuit, when the test lamp is placed in parallel with the DMM. The PCM may be damaged, if either of these conditions are present.

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Use a scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 5 seconds.
  3. Start the engine.

Does the DTC set?

--

Go to Step 3

Go to Diagnostic Aids

3

  1. Turn OFF the ignition.
  2. Disconnect from the powertrain control module (PCM), the harness connector containing the delivered torque signal circuit.
  3. Turn ON the ignition.
  4. Use a DMM in order to measure the voltage between the delivered torque signal circuit and a good ground.

Does the voltage measure greater than the specified value?

10 V

Go to Step 4

Go to Step 5

4

  1. With the DMM still connected to monitor the delivered torque signal circuit, connect one end of a test lamp to a good ground.
  2. Connect the other end of the test lamp to the positive lead of the DMM, while observing the DMM display.

Does the voltage measure less than the specified value?

0.15 V

Go to Step 6

Go to Step 8

5

Test the delivered torque signal circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 11

Go to Step 9

6

Inspect for poor connections at the harness connector of the electronic brake control module (EBCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 11

Go to Step 7

7

Replace the EBCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 11

--

8

Test the delivered torque signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

9

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

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

10

Replace the PCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 11

--

11

  1. Use the scan tool 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 3

System OK