P0712

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

Circuit Description with 4T40-E / 4T45-E Automatic Transaxle
The automatic Transmission Fluid Temperature (TFT) sensor is a thermistor. The TFT sensor is part of the automatic Transmission Fluid Pressure (TFP) manual valve position switch. The PCM supplies a 5-volt reference signal to the sensor. When the transmission fluid is cold, the sensor resistance is high and the PCM senses a high signal voltage. As the transmission fluid warms, the sensor resistance lowers and the PCM senses lower voltage. The PCM uses the TFT reading in order to control the Torque Converter Clutch (TCC), line pressure adjustments, and temperature compensated shifts.

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

CONDITIONS FOR RUNNING THE DTC
^ The ignition switch is in the ON position.
^ The system voltage is 8-18 volts.

CONDITIONS FOR SETTING THE DTC
The TFT voltage is less than 0.33 volts for 10 seconds.

ACTION TAKEN WHEN THE DTC SETS
The PCM does not illuminate the Malfunction Indicator Lamp (MIL).
^ The PCM freezes shift adapts from being updated.
^ The PCM calculates a default transmission fluid temperature based on engine coolant temperature, intake manifold air temperature, and engine run time.
^ The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records.
^ The PCM stores DTC P0712 in PCM history.

CONDITIONS FOR CLEARING THE DTC
^ A scan tool can clear the DTC.
^ The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
^ The PCM 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 PCM.

DIAGNOSTIC AIDS
^ Inspect the connections at the PCM, the TFP manual valve position switch and all other circuit connecting points for an intermittent condition. Refer to Testing for Intermittent and Poor Connections in Diagrams.
^ Inspect the circuit wiring for an intermittent condition. Refer to Testing for Electrical Intermittents in Diagrams.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
3. This step tests the PCMs ability to detect an open circuit.
5. This step tests the TFT sensor for correct resistance.