Circuit Description
The electronic brake control module (EBCM) and the engine control module (ECM) simultaneously control the traction control. The ECM reduces the amount of torque supplied to the drive wheels by retarding spark timing and selective turning off fuel injectors. The EBCM actively applies the brakes to the front wheels in order to reduce torque.
The EBCM sends a requested torque message via serial data communication to the ECM.
When certain ECM diagnostic trouble codes (DTCs) are set, the powertrain control module (PCM) will not be able to perform the torque reduction portion of traction control. A serial data message is sent to the EBCM indicating that traction control is not allowed.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The ECM 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 ECM will typically set a DTC and the EBCM will set this DTC.
Action Taken When the DTC Sets
| • | The EBCM disables the traction control system (TCS) for the duration of the ignition cycle. |
| • | The Traction Off 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 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 |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check-ABS? | Go to Diagnostic System Check - Engine Controls in Engine Controls-2.5L |
