C1278

DTC C1278





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 for the duration of the ignition cycle.
^ 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.