P0727

DTC P0727

Circuit Description

Engine speed information is sent to the transmission control module (TCM) by the engine control module (ECM) through the controller area network (CAN). A two-wire circuit is used to communicate data between the ECM and TCM, CAN H and CAN L. A fault in the CAN will not cause DTC P0727 to set by itself. If a communication fault occurs, other DTCs will set before P0727.

When the ECM sends the TCM an invalid engine speed, DTC P0727 sets. DTC P0727 is a type A DTC.

Conditions for Running the DTC

- No HSCAN DTCs U2103, or U2105.
- The ignition voltage is 8�18 volts.

Conditions for Setting the DTC

The engine speed is invalid for 2.0 seconds.

Action Taken When the DTC Sets

- The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
- The TCM commands maximum line pressure.
- The TCM calculates a default engine speed based on transmission input shaft speed.
- The TCM freezes transmission adaptive functions.
- The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
- The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
- The TCM stores DTC P0727 in TCM history.

Conditions for Clearing the MIL/DTC

- The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
- A scan tool can clear the MIL/DTC.
- The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
- The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.