P2797
DTC P2797 (2.4L Hybrid)
Circuit Description
The auxiliary transmission fluid pump is an electrical device that is used with the auxiliary transmission fluid pump relay to maintain transmission fluid line pressure to the transmission during Engine Idle Off mode. The auxiliary transmission fluid pump attaches to the transmission side cover assembly. The auxiliary transmission fluid pump relay receives voltage through the battery positive voltage circuit. The starter generator control module (SGCM) controls the auxiliary pump by providing the ground path on the auxiliary pump relay control circuit. The SGCM monitors the auxiliary transmission fluid pump relay control circuit voltage.
When the ECM detects the TFP Switch signals do not change state while in Hybrid engine OFF mode, then DTC P2797 sets. DTC P2797 is a type B DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P2797 Auxiliary Transmission Fluid Pump Performance
Conditions for Running the DTC
* The engine is not running and is in Hybrid engine OFF mode.
* The auxiliary transmission fluid pump is commanded ON.
Conditions for Setting the DTC
The auxiliary transmission fluid pump is commanded ON and the transmission fluid pressure (TFP) switches remain open for 30 seconds or more.
Action Taken When the DTC Sets
* The ECM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
* The SGCM inhibits Auxiliary Transmission Fluid Pump operation.
* The SGCM inhibits Engine Idle Off mode.
* 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 ECM stores DTC P2797 in ECM history during the second consecutive trip in which the Conditions for Setting the DTC are met.
Conditions for Clearing the MIL/DTC
* The ECM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
* A scan tool can clear the MIL/DTC.
* The ECM clears the DTC from ECM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
* The ECM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the ECM.
Diagnostic Aids
* Inspect for restricted auxiliary transmission fluid pump pickup filter.
* Inspect for leaking at the auxiliary transmission fluid pump mounting surface.
* Inspect charging system and battery voltage for correct operation.
* Ensure all Engine Idle Off enabling criteria have been met to ensure auxiliary transmission fluid pump operation is possible.
* For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections. Component Tests and General Diagnostics
Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. This step verifies if the auxiliary transmission fluid pump is operational. A stethoscope may be necessary to hear pump running.
4. This step tests for the auxiliary transmission fluid pump pressure.
