GM Service Manual Online
For 1990-2009 cars only

Circuit Description

Traction Control is simultaneously controlled by the EBCM and the PCM. The PCM sends a DELIVERED TORQUE message via a Pulse Width Modulated (PWM) signal to the EBCM confirming the delivered torque level for proper Traction Control system operation. The EBCM supplies the pull up voltage.

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 switch is ON.
    • The DTC can be set after system initialization.

Conditions for Setting the DTC

DTC C0244 can be set anytime when ignition voltage is present. A malfunction exists if the PWM signal is out of range or no signal is received for a period of 2 seconds.

Action Taken When the DTC Sets

If equipped, the following actions occur:

    • The electronic brake control module (EBCM) disables the TCS/VSES for the duration of the ignition cycle.
    • A malfunction DTC will set.
    • The Traction Control Off is turned on. The ABS remains functional.
    • The Stability Off indicator is turned 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 electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

    • It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
    • If an intermittent malfunction exists refer to Checking Aftermarket Accessories .
    • Possible causes for DTC C0244 to set:
       - Open in the Torque Delivered Control circuit.
       - Torque Delivered Control circuit shorted to ground or voltage.
       - Communication frequency problem.
       - Communication duty cycle problem.
       -  Torque Delivered Control circuit has a wiring problem, terminal corrosion, or poor connections.
       - EBCM not receiving information from the PCM.

Test Description

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

  1. Use the scan tool in order to determine if the delivered torque signal has a valid duty cycle.

  2. This vehicle is equipped with a powertrain control module (PCM) which uses an electrically erasable programmable read only memory (EEPROM). When replacing the PCM, the replacement PCM must be programmed.

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 the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Inspect the electronic brake control module (EBCM) ground and powertrain control module (PCM) ground, ensuring each ground is clean and torqued to the proper specification. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 3

3

  1. Install a scan tool.
  2. Start the engine.
  3. With a scan tool, observe the PCM to EBCM Delivered parameter in the Powertrain Control Module data list.

Does the scan tool display the specified value?

90%

Go to Step 4

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

4

  1. Turn OFF the ignition.
  2. Disconnect the EBCM harness connector.
  3. Install the J 39700 Universal Breakout Box using the J 39700-530 Cable Adapter to the EBCM harness connector and the EBCM connector.
  4. Disconnect the PCM harness connector.
  5. Turn ON the ignition, with the engine OFF.
  6. Measure the voltage from the delivered torque signal circuit to a good ground.

Does the voltage measure near the specified value?

B+

Go to Step 5

Go to Step 6

5

  1. Turn OFF the ignition.
  2. Disconnect the cable adapter from the EBCM connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Test the delivered torque signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 7

6

  1. Turn OFF the ignition.
  2. Disconnect the cable adapter from the EBCM connector.
  3. Test the delivered torque signal circuit for the following conditions:
  4. • An open
    • A short to ground
    • A high resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 8

7

Inspect for poor connections at the harness connector of the PCM. 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 11

Go to Step 9

8

Inspect for poor connections at the harness connector of 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 11

Go to Step 10

9

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

Did you complete the repair?

--

Go to Step 11

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10

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 11

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11

  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?

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Go to Step 2

System OK