Circuit Description
The PCM monitors various parameters and will not allow traction control operation if any parameter falls outside a specified range.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C1278 TCS Temporarily Inhibited by PCM
Conditions for Running the DTC
The ignition is ON.
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
| • | The EBCM disables the TCS until the DTC becomes a history DTC. |
| • | The Traction Off indicator turns ON. |
| • | The 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 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 |
