Diagnostic Instructions

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

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
TFT Sensor Signal	P0712	P0713	P0713	P0218, P0711
Low Reference	--	P0713	--	P0218, P0711

Typical Scan Tool Data

Trans. Fluid Temp.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Operating Conditions: Engine running in PARK, normal operating temperature Parameter Normal Range: -40 to +149°C (-40 to +300°F)
Trans. Fluid Temp.	Greater than 149°C (300°F)	Less than -40°C (-40°F)	Less than -40°C (-40°F)

Circuit/System Description

The automatic TFT sensor is a thermistor. The TFT sensor is part of the automatic transmission fluid pressure (TFP) manual valve position switch. The powertrain control module (PCM) supplies a 5-volt reference signal to the sensor. When the transmission fluid is cold, the sensor resistance is high and the PCM senses a high signal voltage. As the transmission fluid warms, the sensor resistance lowers and the PCM senses lower voltage. The PCM 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

Conditions for Setting the DTC

P0712

TFT is 150°C (302°F) or greater for 10 seconds.

P0713

TFT is -40°C (-40°F) or less for 400 seconds (7 minutes).

Action Taken When the DTC Sets

Conditions for Clearing the DTC

DTC P0712 and P0713 are type C DTCs.

Diagnostic Aids

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

Circuit/System Verification

Circuit/System Testing

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, using the J 44257 main wiring harness connector remover, disconnect the automatic transmission inline 20-way connector and install the J 44152 jumper harness on the transmission pass-thru connector.
2. Using the light blue J 35616-65B test probes from the J 35616-D GM terminal test kit, test for 3,164-3,867 ohms at 20°C (68°F) between the TFT sensor signal circuit, jumper harness pin L, and the TFT low reference circuit, jumper harness pin M. Refer to Transmission Fluid Temperature Sensor Specifications for the resistance at other temperatures.

⇒	If greater than the specified range, test the affected circuits for an open/high resistance. If both circuits test normal, test the engine side of the TFT sensor signal circuit for a short to voltage AND replace the TFT sensor.

⇒	If less than the specified range, test the affected circuits for a shorted together condition. If both circuits test normal, replace the TFT sensor.

3. Test for greater than 10K ohms between the TFT sensor signal circuit, jumper harness pin L, and all other circuits of the J 44152 jumper harness, except the TFT low reference circuit, jumper harness pin M.

⇒	If less than the specified range, the affected circuits are shorted together. Replace the transmission internal wire harness.

4. Test for greater than 250 M ohms from the TFT sensor signal circuit, jumper harness pin L, and the TFT low reference circuit, jumper harness pin M, to the transmission case.

⇒	If less than the specified value, the affected circuit is shorted to the transmission case. Replace the transmission internal wire harness.

5. Using the J 44257 main wiring harness connector remover, remove the J 44152 jumper harness from the transmission pass-thru connector and install it on the engine side of the automatic transmission inline 20-way connector.
6. Disconnect the X3 harness connector at the PCM.

Important: When probing a terminal for testing procedures, it is imperative to use the proper test probe from the J 35616-D GM terminal test kit. Prior versions of the J 35616 GM terminal test kit do not contain the proper probes for testing TCM/ECM/PCM connectors. TCM/ECM/PCM harnesses use 0.64 mm (0.03 in) round terminals. The correct probe for this size terminal is the light blue J 35616-64B probe. ALL PREVIOUS J 35616-64 AND J 35616-64A PROBES SHOULD BE DISCARDED. The 1.00 mm (0.04 in) brown J 35616-6 probe is most widely mistaken for use with 0.64 mm (0.03 in) terminals. Use of the 1.00 mm (0.04 in) brown probe in a 0.64 mm (0.03 in) terminal will deform the terminal, likely resulting in an intermittent open condition.

7. Using the light blue J 35616-64B probes from the J 35616-D GM terminal test kit, test for greater than 250 M ohms from the TFT sensor signal circuit, jumper harness terminal L, and the TFT low reference circuit, jumper harness terminal M, to a good ground.

⇒	If less than the specified value, test the affected circuit for a short to ground.

8. Using the light blue J 35616-64B probes, test for greater than 10K ohms between the TFT sensor signal circuit, jumper harness pin L, and all other circuits of the J 44152 jumper harness.

⇒	If less than the specified value, the affected circuits are shorted together.

9. Using the light blue J 35616-64B probes, test for greater than 10K ohms between the TFT low reference circuit, jumper harness terminal M, and all other circuits of the J 44152 jumper harness.

⇒	If less than the specified value, the affected circuits are shorted together.

10. Using the light blue J 35616-64B probes, test the TFT sensor signal circuit for less than 10 ohms between the J 44152 jumper harness terminal L and terminal 5 of the PCM X3.

⇒	If greater than the specified value, repair the open or high resistance in the affected circuit.

11. Using the light blue J 35616-64B probes, test the TFT low reference circuit for less than 10 ohms between the J 44152 jumper harness terminal M and terminal 48 of the PCM X3.

⇒	If greater than the specified value, repair the open or high resistance in the affected circuit.

12. Using a 5A fused jumper wire and the light blue J 35616-64B probes, test for greater than 10K ohms between the TFT sensor signal circuit, terminal 5 PCM X3, and all other circuits of the PCM X3.

⇒	If less than the specified value, the affected circuits are shorted together.

13. Using a 5A fused jumper wire and the light blue J 35616-64B probes, test for greater than 10K ohms between the TFT low reference circuit, terminal 48 PCM X3, and all other circuits of the PCM X3.

⇒	If less than the specified value, the affected circuits are shorted together.

14. If all circuits and connections test normal, replace the PCM.

Component Testing

1. Using the light blue J 35616-65B test probes from the J 35616-D GM terminal test kit, test for 3,164-3,867 ohms at 20°C (68°F) between the TFT sensor signal circuit, jumper harness pin L, and the TFT low reference circuit, jumper harness pin M. Refer to Transmission Fluid Temperature Sensor Specifications for the resistance at other temperatures.

⇒	If greater than the specified range, test the affected circuits for an open/high resistance. If both circuits test normal, test the engine side of the TFT sensor signal circuit for a short to voltage AND replace the TFT sensor.

⇒	⇒ If less than the specified range, test the affected circuits for a shorted together condition. If both circuits test normal, replace the TFT sensor.

2. Test the PCM for supplying a 5-volt reference to the TFT sensor signal circuit, jumper harness pin L.

⇒	If the PCM is not supplying a 5-volt reference to the TFT sensor, replace the PCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.