GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The electronic brake control module (EBCM) and the powertrain control module (PCM) simultaneously control the traction control. The EBCM sends a serial data message to the PCM requesting torque reduction. When certain PCM DTCs are set, the PCM will not be able to perform the torque reduction for traction control. A serial data message is sent to the EBCM indicating that traction control is not allowed.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0242 Powertrain Control Module (PCM) Indicated TCS Malfunction

Conditions for Running the DTC

    • The ignition is ON.
    • Ignition voltage is greater than 8 volts.

Conditions for Setting the DTC

The PCM diagnoses a condition preventing the engine control portion of the traction control function and sends a serial data message to the EBCM indicating that torque reduction is not allowed. The PCM will typically set a DTC and the EBCM will set this DTC.

Action Taken When the DTC Sets

If equipped, the following actions occur:

    • The EBCM disables the traction control system (TCS)/vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
    • The Traction Control and Active Handling indicator turns ON.
    • The driver information center (DIC) displays the following messages:
       - Service Traction System
       - Service Active Handling
    • The antilock brake system (ABS) remains functional.

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

This DTC is for information only. As an aid to the technician, this DTC indicates that there are no problems in the ABS/TCS system.

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

1

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