C0240

DTC C0240

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptors
DTC C0240
- ECM Traction Control Not Allowed

Circuit/System Description

C0240

The engine control module (ECM) and the electronic brake control module (EBCM) communicate on the serial data link, whenever the ignition is ON.

Conditions for Running the DTC

C0240

Ignition ON.

Conditions for Setting the DTC

C0240

The EBCM receives a serial data message stating that the ECM has lost the ability to reduce engine torque.

Action Taken When the DTC Sets

C0240
* The EBCM disables the traction control system (TCS) and vehicle stability enhancement system (VSES).
* A DIC message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

* The condition for the DTC is no longer present.
* The EBCM clears the history DTC when a current DTC is not detected in 50 consecutive drive cycles.

Reference Information
Schematic Reference

Antilock Brake System Schematics ([1][2]Antilock Brakes / Traction Control Systems)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

ABS Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information.

Circuit/System Testing

Important: It is recommend that the defective components be replaced, and not the complete brake master cylinder assembly.


1. Ignition OFF, disconnect the harness connector at the EBCM.
2. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal 23 and ground.

• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

3. If the circuits test normal, replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning) for EBCM or ECM replacement, setup, and programming