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 ACTIVE



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








Is the resistance below 5.0 ohms?

Yes


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
  










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

4.INTERMITTENT WIRING AND CONNECTORS





Were there any problems found?

Yes


No
  • Test Complete.