FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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4L80-E/4L85-E - Automatic Transmission



DTC P0712 or P0713

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provide an overview of each diagnostic category.



DTC Descriptors
DTC P0712
- Transmission Fluid Temperature (TFT) Sensor Circuit Low Voltage

DTC P0713
- Transmission Fluid Temperature (TFT) Sensor Circuit High Voltage




Diagnostic Fault Information






Typical Scan Tool Data






Circuit/System Description

The automatic TFT sensor is a thermistor type sensor. The transmission control module (TCM) supplies a 5-volt reference signal to the sensor. When the transmission fluid is cold, the sensor resistance is high and the TCM senses a high signal voltage. As the transmission fluid warms, the sensor resistance lowers and the TCM senses lower voltage. The TCM uses the TFT reading in order to control the torque converter clutch (TCC), line pressure adjustments, and temperature compensated shifts.


Conditions for Running the DTC


P0712
* The ignition voltage is between 8 and 18-volts.
* The engine speed is between 500 and 6,500 RPM for 5 seconds.



P0713
* DTC P0716, P0717, P0722, or P0723 is not set.
* The ignition voltage is between 8 and 18-volts.
* The engine speed is between 500 and 6,500 RPM for 5 seconds.
* The transmission output shaft speed is 200 RPM or greater for 200 seconds cumulatively.
* The TCC slip speed is 200 RPM or greater for 200 seconds cumulatively.



Conditions for Setting the DTC

P0712

The TFT sensor is greater than 150°C (302°F) for 12 seconds.

P0713

The TFT is less than -40°C (-40°F) for 80 seconds.


Action Taken When the DTC Sets

DTC P0712 and P0713 are type C DTCs.


Conditions for Clearing the DTC

DTC P0712 and P0713 are type C DTCs.


Reference Information
Schematic Reference

Automatic Transmission Controls Schematics (6.6L) (Electrical Diagrams)Automatic Transmission Controls Schematics (4.8L and 6.0L) (Electrical Diagrams)
Connector End View Reference

Component Connector End Views
Description and Operation

Transmission General Description (Transmission General Description)
Electrical Information Reference

* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference

Control Module References for scan tool information
Special Tools

* J 35616 GM Terminal Test Kit
* J 44152 Jumper Harness (20 pins)



Circuit/System Verification

1. Start the engine.
2. The vehicle in PARK and at normal operating temperature, observe the Trans. Fluid Temp. parameter on the scan tool. The Trans. Fluid Temp. should display a temperature near the ECT sensor parameter.



Circuit/System Testing

1. Ignition OFF, disconnect the transmission 20-way harness connector.
2. Ignition OFF, test the TCM side of the transmission 20-way harness connector for less than 5 ohms of resistance between the low reference circuit terminal M and ground.

If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the TCM.

3. Ignition ON, verify that the TFT sensor parameter is at -40°C (-40°F).

If greater than the specified range, test the TCM side of the 20-way harness connector signal circuit terminal L for a short to ground. If the circuit tests normal, replace the TCM.


Important: If the signal circuit of the TFT sensor is shorted to voltage the TFT sensor may be damaged.


4. Install a 3-amp fused jumper wire between the signal circuit terminal L and the low reference circuit terminal M on the TCM side of the transmission 20-way harness connector. Verify the TFT sensor parameter is greater than 128°C (262°F).

If less than the specified range, test the signal circuit of the TFT sensor for a short to voltage or an open/high resistance. If the circuit tests normal, replace the TCM.

5. If all circuits test normal, test or replace the internal transmission wiring harness or the TFT sensor.



Component Testing

Install the J 44152 jumper harness (20 pins) on the transmission side of the automatic transmission 20-way inline connector. Using the J 35616 GM terminal test kit, measure the resistance between the TFT sensor signal circuit and the low reference circuit. Refer to Transmission Fluid Temperature Sensor Specifications (4L60-E/4L65-E/4L70-E - Automatic Transmission) .

If the resistance is not within the specified range, replace the transmission wiring harness or the TFT sensor.



Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.


Valve Body and Pressure Switch Replacement (4L80-E/4L85-E - Automatic Transmission) .


Control Module References for TCM replacement, setup, and programming.