GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC C0240 00: ECM Traction Control Not Allowed

Circuit/System Description

The engine control module (ECM) monitors various parameters and will not allow traction control system (TCS) operation if any parameter falls outside a specified range.

Conditions for Running the DTC

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

Conditions for Setting the DTC

The ECM sends a GMLAN serial data message to the electronic brake control module (EBCM) indicating that torque reduction is temporarily not allowed.

Action Taken When the DTC Sets

    • The EBCM disables the TCS until the DTC becomes a history DTC.
    • The vehicle dynamics caution (VDC) indicator turns ON.
    • 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 electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

This DTC indicates that there are no problems in the ABS or TCS. Diagnose any DTCs that are set in in the ECM.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for Scan Tool Information