Powertrain Control Module (PCM) - 66RFE

P0714-TRANSMISSION TEMPERATURE SENSOR INTERMITTENT

Special Tools:






For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Transmission Temperature Sensor is a variable resistor that changes with temperature or otherwise known as a thermistor. The temperature of the transmission fluid can affect a variety of electronically controlled transmission operations such as shift quality, torque converter lock-up and/or when certain OBDII system self-diagnostic tests are performed. The Powertrain Control Module (PCM) substitutes a calculated transmission temperature value if a fault is detected in the Transmission Temperature Sensor circuit.

- When Monitored:
Continuously with the ignition on and engine running.

- Set Condition:
The DTC will set when the monitored Temperature Sensor voltage fluctuates or changes abruptly within a predetermined period of time.





Always perform the Pre-Diagnostic Troubleshooting Procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. DETERMINE IF RELATED DTCs ARE PRESENT
1. With the scan tool, read DTCs.

Are any line pressure sensor or throttle position sensor DTCs present?

Yes
Perform the appropriate diagnostic procedure.
No

- Go To 2

2. CHECK IF THE DTC IS CURRENT
1. With the scan tool, read DTCs.

Is the status Active or is the Starts Since Set counter 2 or less for this DTC?

Yes

- Go To 3

No

- Go To 4

3. TRANSMISSION TEMPERATURE SENSOR
1. Turn the ignition OFF to the LOCK position.
2. Remove the Ignition Switch Feed fuse from the TIPM.

CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being started in gear.

WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in possible serious or fatal injury.

3. Install the (8333A).
4. Ignition ON, Engine Not Running.
5. With the Transmission Simulator, turn the Input/Output switch to OFF.
6. With the scan tool, monitor the TRANS TEMP VOLTS while turning the Thermistor Voltage switch to all three positions on the Transmission Simulator.
7. Compare the scan tool readings with the numbers listed on the Transmission Simulator.

Do the readings on the Transmission Simulator match a non-fluctuating scan tool reading ± 0.2 volts?

Yes

- Replace the Transmission Solenoid/TRS Assembly.
- Perform the 66RFE TRANSMISSION VERIFICATION TEST. 66RFE Transmission Verification Test

No

- Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the PCM. With the scan tool, perform a Quick Learn.
- Perform the 66RFE TRANSMISSION VERIFICATION TEST. 66RFE Transmission Verification Test

4. CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set this DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
3. Wiggle the wires while checking for shorted and open circuits.
4. With the scan tool, check the Event Data to help identify the conditions in which the DTC set.

Were any problems found?

Yes

- Repair as necessary.
- Perform the 66RFE TRANSMISSION VERIFICATION TEST. 66RFE Transmission Verification Test

No

- Test Complete.