4L80-E / 4L85-E Automatic Transmission

DTC P0713





Test 1-5





Test 6-9

Circuit Description with 4L80-E / 4L85-E Automatic Transmission
The automatic Transmission Fluid Temperature (TFT) sensor is part of the 4L80-E Automatic Transmission (AT) wiring harness assembly. 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 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 C DTC.

Conditions for Running the DTC
The ignition is ON.

Conditions for Setting the DTC
^ The TFT sensor indicates a voltage greater than 4.94 volts.
^ All conditions are met for 400 seconds (6.6 minutes).

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 Fluid Temperature (TFT) using the following matrix:
- If the Engine Coolant Temperature (ECT) is less than -30°C (-22°F) then default TFT is set to -28°C (-19°F).
- If the ECT is -30 to +110°C (-22 to +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).

^ 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 P0713 in PCM history.

Conditions for Clearing the DTC
^ A scan tool clears the DTC from PCM history.
^ 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 the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
^ 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.
^ DTC P0713 defaults to an elevated line pressure condition which may result in partial TCC apply. This may produce an idle surge that could stall the engine.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. This step verifies a condition in the TFT sensor circuit.
5. This step tests for higher than normal circuit voltage, which may also damage the TFT sensor.