P0726

DTC P0726

Circuit Description

The transmission control module (TCM) is an electronic device which monitors inputs to control various transaxle functions including shift quality and transaxle sensors, switches, and components to process for use within the control program. Based on this input information, the TCM controls various transaxle output functions and devices.

DTCs P0725, P0726 and P0727 are related to the same circuit. These DTCs will not illuminate the HOLD or malfunction indicator lamp (MIL), however, the DTC will be stored in memory.

Information transmits between the TCM and engine control module (ECM) through the controller area network (CAN) line. Information is as follows :

* Engine malfunction signal
* Engine speed
* Engine output torque reduction signal
* Engine coolant temperature

Conditions for Setting the DTC

* Gear position is D.
* The engine speed is greater than 7,000 RPM.
* System voltage is greater than 8.5 volts.
* The engine is running
* CAN transmitting wiring harness shorted or open
* The TCM or ECM is defective.
* When turbine speed is more than 1,500 RPM, engine speed is less than 400 RPM.
* Immediately after the above condition occurs

Action Taken When the DTC Sets

* No lamp control
* The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.
* Adopt Emergency/Substitute mode and constant 4th gear.
* Open lock up clutch

Conditions for Clearing the MIL/DTC

* A history DTC will clear after 40 consecutive warm-up cycles without a fault.
* Using a scan tool can clear history DTCs.

Diagnostic Aids

* Inspect the poor wiring harness connection for TCM connectors and transaxle wiring connectors.
* Inspect the improperly formed or damaged terminals.