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 engine torque reduction is not allowed.
This diagnostic procedure supports the following DTC:
DTC C0242 PCM Indicated TCS Malfunction
| • | The ignition is ON. | 
| • | Ignition voltage is greater than 8 volts. | 
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.
| • | The EBCM disables the traction control system (TCS) for the duration of the ignition cycle. | 
| • | The Traction Off indicator turns ON. | 
| • | The ABS remains functional. | 
| • | 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. | 
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  | Did you perform the Diagnostic System Check - Vehicle?  | --  | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information  |