LCT 1000 Allison Transmission
DTC P0713
Circuit Description
The transmission fluid temperature (TFT) sensor is part of the pressure switch manifold (PSM) assembly, and is located in the transmission oil pan. The transmission control module (TCM) supplies a 5-volt reference voltage signal to the TFT sensor and measures the voltage drop in the circuit. When the transmission is cold, the sensor resistance is high and the TCM detects high signal voltage. As the fluid temperature warms to a normal operating temperature, the resistance becomes less and the signal voltage decreases. The TCM uses this information to control shift quality and torque converter clutch (TCC) apply.
DTC P0713 is a type B DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0713 Transmission Fluid Temperature (TFT) Sensor Circuit - High Input
Conditions for Running the DTC
* DTC P0711 and P0712 are not active.
* The components are powered and ignition voltage is greater than 9.0 volts and less than 18 volts.
* Engine speed is greater than 200 RPM and less than 7,500 RPM for 5 seconds.
* The engine has been running for20 seconds with a coolant temperature above 20°C (68°F).
Conditions for Setting the DTC
DTC P0713 sets when the TCM detects a voltage greater than 4.84 volts for 2.5 seconds.
Action Taken When the DTC Sets
* The TCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
* The TCM uses a TFT default value.
* The TCM freezes shift adapts.
* The TCM stores this information as Failure Records.
* The TCM stores DTC P0713 in TCM history.
* The TCM inhibits TCC engagement.
Conditions for Clearing the DTC
A scan tool can clear the code from TCM history. The TCM automatically clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without failure.
Diagnostic Aids
* Inspect the wiring for poor electrical connections at the TCM. Inspect for 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
* When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.
* You may have to drive the vehicle in order to experience a condition.
* A short to power will allow DTC P0713 to set.
* A short to power may also damage the TFT sensor.
Test Description
The numbers below refer to the step numbers on the diagnostic table
4. This step tests 5-volt reference.
6. This step tests the TFT sensor and internal wiring harness.
7. This step tests the resistance of the TFT sensor.
