With Powertrain Control Module

Wiring Diagram:

CIRCUIT DESCRIPTION

The Automatic Transmission Fluid Temperature (TFT) Sensor is part of the 4L80-E Automatic Transmission Wiring Harness Assembly (A/T Wiring Harness Assy.). The TFT Sensor is a resistor, or thermistor, which changes value based on temperature. The sensor has a negative-temperature coefficient. This means that as the temperature increases, the resistance decreases, and as the temperature decreases the resistance increases. The Powertrain Control Module (PCM) supplies a 5-volt reference signal to the sensor on circuit 1227 and measures the voltage drop in the circuit. When the transmission fluid is cold, the sensor resistance is high and the PCM detects high signal voltage. As the fluid temperature warms to a normal operating temperature, the resistance becomes less and the signal voltage decreases. The PCM uses this information to control shift quality and torque converter clutch apply.

DTC P0713 is a type D DTC.

CONDITIONS FOR SETTING THE DTC

^ The ignition is ON.

^ The TFT Sensor indicates a voltage greater than 4.94 volts.

^ All conditions are met for 400 seconds.

ACTION TAKEN WHEN THE DTC SETS

^ The PCM does not illuminate the Malfunction Indicator Lamp (MIL).

^ The PCM commands increased line pressure.

^ The PCM freezes shift adapts.

^ The PCM determines a TFT default Transmission Temperature (TFT) using the following matrix:

- If the Engine Run Time is less than 60 seconds then Default TFT equals the Intake AIR Temperature (IAT), plus 5 degrees.

- If the Engine Coolant Temperature (ECT) is less than 85°C (185°F) then Default TFT equals IAT plus 10 degrees.

- If the ECT is 85°-110°C (185°-230°F) then Default TFT equals ECT plus 10 degrees.

- If the ECT is greater 110°C (230°F) then Default TFT is set to 140°C (284°F) and transmission shift pattern is in Hot Mode.

- If ECT and TFT DTCs are both set then Default TFT is 140°C (284°F).

^ DTC P0713 is stored in PCM history.

CONDTIONS FOR CLEARING THE DTC

^ A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.

^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

DIAGNOSTIC AIDS

^ Inspect the wiring at the PCM, the transmission connector and all other circuit connecting points (or the following conditions:

- A bent terminal

- A backed out terminal

- A damaged terminal

- Poor terminal tension

- A chafed wire

- A broken wire inside the insulation.

- Moisture intrusion

- Corrosion

^ When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.

^ First diagnose and clear any engine DTCs or TP Sensor DTCs that are present. Then inspect for any transmission DTCs that may have reset.

^ DTC P0218 may set approximately 600 seconds after DTC P0713 has set. Follow the diagnostic table for DTC P0713 before proceeding to the diagnostic table for DTC P0218.

TEST DESCRIPTION

The numbers below refer to the step numbers on the diagnostic table.

4. This step tests for higher than normal circuit voltage which may also damage the TFT Sensor.

6. This step simulates a TFT Sensor DTC P0712. If the PCM recognizes the low signal voltage (high temperature), and the scan tool displays 146°C (295°F) or greater, the PCM and the wiring are OK.

7. This step verifies a problem in the TFT Sensor circuit.

8. This step inspects the TFT sensor and the Air Wiring Harness Assy. for an open.