P0712-TRANSMISSION TEMPERATURE SENSOR LOW
For a complete wiring diagram Refer to Section 8W.
Theory of Operation
The Transmission Control Module (TCM) monitors the Transmission Temperature Sensor Signal circuit for voltage changes within desired limits. The TCM calculates the transmission fluid temperature from the temperature sensor signal voltage. This value is used in conjunction with various other inputs to calibrate different operating modes such as Torque Converter lock-up and Torque reduction.
The Transmission Temperature Sensor is a thermistor that changes resistive value when subject to different temperatures. When the monitored voltage rises, the calculated temperature decreases.
- When Monitored:
Ignition on with battery voltage between 9.0 and 16.0 volts.
Vehicle speed greater than 10 Km/h (6 mph).
No secondary speed sensor or sensor ground DTCs detected.
- Set Condition:
Indicated temperature is greater than 180° C (356° F) for the continuous period of 5 seconds.
| Possible Causes |
| (T54) TRANSMISSION TEMPERATURE SENSOR SIGNAL CIRCUIT SHORT TO GROUND |
| TRANSMISSION TEMPERATURE SENSOR |
| TRANSMISSION CONTROL MODULE |
Always perform the CVT Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - CVT - STANDARD PROCEDURE)
Diagnostic Test
1. CHECK IF THE DTC IS ACTIVEWith the scan tool, read Transmission DTCs.
Is the status Active or is the STARTS SINCE SET counter 2 or less for this DTC?
Yes
- Go To 2
No
- Go To 4
2. CHECK THE (T54) TRANSMISSION TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
Turn the ignition off to the lock position.
Disconnect the TCM C2 harness connector.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Measure the resistance between ground and the (T54) Transmission Temperature Sensor Signal circuit.
Is the resistance below 5.0 ohms?
Yes
- Repair the (T54) Transmission Temperature Sensor Signal circuit for a short to ground.
- Perform CVT VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - CVT - STANDARD PROCEDURE)
No
- Go To 3
3. CHECK THE (T54) TRANSMISSION TEMPERATURE SENSOR
| Temperature Sensor Resistive Values Chart | |
| Transmission Temperature | Resistive Value Compared to Temperature (± 10%) |
| 20° C (68° F) | 2.5k to 6.5k ohms |
| 80° C (176° F) | 0.3k to 0.9k ohms |
Reconnect all previously disconnected connectors.
Start the engine and allow to obtain normal operating temperature (approximately 10 min. of engine run time).
Turn the ignition off to the lock position.
Disconnect the TCM C2 harness connector.
Measure the resistance between the (T54) Transmission Temperature Sensor Signal circuit and the (T13) Sensor Ground circuit in the TCM C2 harness connector.
Is the resistance within the desired range listed on the above chart?
Yes
- Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. Check for any Service Bulletins for possible causes that may apply. If no problems are found, replace the TCM per the Service Information.
- Perform CVT VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - CVT - STANDARD PROCEDURE)
No
- Replace the CV Transmission or the Transmission Temperature Sensor (Valve Body) per the Service Information.
- Perform CVT VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - CVT - STANDARD PROCEDURE)
4. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
Wiggle the wires while checking for shorted and open circuits.
Were there any problems found?
Yes
- Repair as necessary.
- Perform CVT VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - CVT - STANDARD PROCEDURE)
No
- Test Complete.