4T80-E Automatic Transaxle

DTC P0712





Circuit Description
The automatic transmission fluid temperature (TFT) sensor is a negative coefficient thermistor whose resistance value changes based on temperature. The transmission control module (TCM) provides a 5 volt reference to the sensor. A high fluid temperature or a short to ground on the signal circuit results in low signal voltage. The TFT operating range is -40 to +150°C (-40 to +302°F).

If the TCM detects a continuous short to ground in the TFT sensor circuit, then DTC P0712 sets. DTC P0712 is a type C DTC.

DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0712 Transmission Fluid Temperature (TFT) Sensor Circuit Low Voltage

Conditions for Running the DTC
^ No Trans. Temp. DTC's P0218, P0711 or P0713.
^ The engine run time is greater than 5 seconds.

Conditions for Setting the DTC
The TCM detects a TFT of greater than 150°C (302°F) for 12 seconds.

Action Taken When the DTC Sets
^ The TCM does not request the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL).
^ The TCM freezes transmission adaptive functions.
^ The TCM calculates a default transmission fluid temperature based on engine coolant temperature, intake air temperature and engine run time.
^ 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 P0712 in TCM history.

Conditions for Clearing the DTC
^ The TCM clears the DIC message when the condition no longer exists.
^ A scan tool can clear the DIC/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 fault no longer exists and the DTC passes.

Test Description

Step 1 - Step 7:

Step 8 - Step 12:

The numbers below refer to the step numbers on the diagnostic table.
2. This step verifies DTC P0712 by indicating a short to ground. If the scan tool does not display a transmission fluid temperature greater than 150°C (302°F), then the DTC is intermittent.
3. This step isolates the transmission. If the scan tool displays a transmission fluid temperature less than -38°C (-36°F), then the engine wiring harness is good.