P1793

DTC P1793

Test 1-7:

Circuit Description
The Engine Control Module (ECM) sends wheel speed data to the Transmission Control Module (TCM). The data is sent to the TCM through a communication network called the Controller Area Network (CAN). Two circuits are used to communicate CAN data between the ECM and TCM. A fault in the CAN will not cause DTC P1793 to set by itself. If a CAN fault occurs, other DTCs will set before DTC P1793.

When the TCM receives invalid wheel speed data from the ECM, then DTC P1793 will set. DTC P1793 is a type C DTC.

Conditions for Running the DTC
^ The engine run time is greater than 5 seconds.
^ No other CAN errors are present.

Conditions for Setting the DTC
The TCM receives no valid wheel speed data from the ECM for 2 seconds.

Action Taken When the DTC Sets
^ The TCM does not request the ECM to illuminate the Malfunction Indicator Lamp (MIL).
^ The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
^ The TCM stores DTC P1793 in TCM history.

Conditions for Clearing the DTC
^ A scan tool can clear the DTC.
^ The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
^ The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.