P0712
DTC P0712 or P0713
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
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
Circuit/System Description
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 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
DTC P0712
The engine is running for 5 seconds.
DTC P0713
* No ISS DTCs P0716 or P0717.
* No OSS DTCs P0722 or P0723.
* The engine is running for 5 seconds.
* The output speed is 200 RPM or more for 200 seconds cumulatively.
* The TCC slip speed is 120 RPM or more for 200 seconds cumulatively.
Conditions for Setting the DTC
DTC P0712
The TFT sensor is greater than 150°C (302°F) for 12 seconds.
DTC P0713
The TFT is less than -40°C (-40°F) for 1 minute and 20 seconds.
Action Taken When the DTC Sets
* DTCs P0712 and P0713 are Type C DTCs.
* The TCM freezes transmission adaptive functions.
* The TCM calculates a default transmission fluid temperature based on engine coolant temperature, intake manifold air temperature, and engine run time.
Conditions for Clearing the DTC
DTCs P0712 and P0713 are Type C DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
* Automatic Transmission Inline 20-Way Connector End View
* Automatic Transmission Internal Connector End Views
* Automatic Transmission Related Connector End Views
Electrical Information Reference
* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs
Scan Tool Reference
* Scan Tool Data List
* Scan Tool Data Definitions
* Scan Tool Output Controls
Special Tools Required
* J 35616 GM Terminal Test Kit
* J 44152 Jumper Harness (20 pins)
Circuit/System Verification
Start the engine. With 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 near the ECT sensor parameter.
Circuit/System Testing
1. Disconnect the AT 20-way inline connector. Using a DMM and the J 35616, measure the voltage at the TFT sensor signal circuit at the engine side of the connector. The voltage should be 4.9-5.1 volts.
Important: If a short to voltage is found, test the TFT sensor for damage.
- If the voltage is less than the specified range, test the TFT sensor signal circuit for an open, high resistance, or short to ground.
- If the voltage is above the specified range, test the TFT sensor signal circuit for a short to voltage.
2. Using the J 35616, measure the voltage between the TFT sensor signal circuit and the low reference circuit at the engine side of the AT 20-way inline connector. The voltage should be 4.9-5.1 volts.
- If the voltage is less than the specified value, test the low reference circuit for an open, high resistance, or short to ground.
3. Install the J 44152 Jumper Harness on the transmission side of the AT 20-way inline connector. Using the J 35616, measure the resistance between the TFT sensor signal circuit and the low reference circuit. Refer to Temperature Versus Resistance for the 2.2L engine or Temperature Versus Resistance for the 2.4L engine for the resistance values.
- If the resistance is greater than the specified range for a given temperature, test the TFT sensor signal circuit and the low reference circuit for an open or high resistance.
- If the resistance is less than the specified range, test the TFT sensor signal circuit and the low reference for a shorted together condition or a faulty TFT sensor.
- If a shorted together condition is found, replace the transmission wiring harness.
4. Using the J 35616, measure the resistance between the TFT sensor signal circuit and the transmission case. The resistance should be greater than 10K ohms.
- If the resistance is less than 10K ohms, test the TFT sensor signal circuit for a short to the transmission case.
- If a short to the case is found, replace the transmission wiring harness.
5. Using the J 35616, measure the resistance between the low reference circuit and the transmission case. The resistance should be greater than 10K ohms.
- If the resistance is less than 10K ohms, test the low reference circuit for a short to the transmission case.
- If a short to the case is found, replace the transmission wiring harness.
6. Using the J 35616, measure the resistance between the TFT sensor signal circuit and all other circuits of the J 44152 jumper harness except the low reference circuit. The resistance should be greater than 10K ohms.
- If the resistance is less than 10K ohms, replace the transmission wiring harness.
- If all circuits/connections test normal, test the TFT sensor.
Component Testing
Install the J 44152 on the transmission side of the AT 20-way inline connector. Using the J 35616 measure the resistance between the TFT sensor signal circuit and the low reference circuit. Refer to Temperature Versus Resistance for the 2.2L engine or Temperature Versus Resistance for the 2.4L engine for the resistance values.
If the resistance is not within the specified range, replace the transmission wiring harness.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair. Verification Tests
* Ensure the transmission fluid temperature is between -39 and +149°C (-38 and +300°F) for at least 10 seconds.
* Programming and Relearning. Programming and Relearning
* Wiring Harness Replacement