P0712-TRANSMISSION TEMPERATURE SENSOR LOW





For a complete wiring diagram Refer to Section 8W.

Theory of Operation


The temperature sensor is used to sense the temperature of the transmission fluid. Transmission fluid temperature can affect shift quality, torque converter operation and when or if some diagnostics are run. A failed temperature sensor could affect the OBD diagnostics. If a problem occurs in the transmission temperature sensor circuit, transmission temperature will be based on a calculated value.


  • When Monitored:

    Continuously with the ignition on and engine running.

  • Set Condition:

    The DTC will set when the monitored Temperature Sensor voltage drops below 0.078 volts for the period of 1.45 seconds. When the fault is set, calculated temperature is substituted for measured temperature, however the fault code is stored only after three consecutive occurrences of the fault.


Possible Causes
  
RELATED DTCS PRESENT
  
(T54) TRANSMISSION TEMPERATURE SENSOR SIGNAL CIRCUIT SHORT TO GROUND
  
TRANSMISSION TEMPERATURE SENSOR
  
POWERTRAIN CONTROL MODULE
  

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)



Diagnostic Test

1.DETERMINE IF RELATED DTCS ARE PRESENT



Are there any Speed Sensor DTCs present?

Yes


No
  • Go To 2

2.CHECK TO SEE IF DTC IS ACTIVE



Is the status Active for this DTC or is the STARTS SINCE SET counter 2 or less?

Yes
  • Go To 3


No
  • Go To 5

3.CHECK THE PCM AND WIRING WITH THE TRANSMISSION SIMULATOR



CAUTION: Removal of the Starter Relay is to prevent a Transmission NO RESPONSE condition and to disable the starter.



NOTE: Check connectors - Clean/repair as necessary.







Do the readings on the Transmission Simulator match the scan tool readings ± 0.2 volts?

Yes


No
  • Go To 4

4.CHECK THE (T54) TRANSMISSION TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND






NOTE: Check connectors - Clean/repair as necessary.


CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Tool #8815 to perform diagnosis.




Is the resistance below 5.0 ohms?

Yes


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. Check for Service Information Tune-ups or Service Bulletins for any possible causes that may apply. If no problems are found, replace and program the PCM per the Service Information. With the scan tool, perform QUICK LEARN.
  • Perform 42RLE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)

5.INTERMITTENT WIRING AND CONNECTORS







Were there any problems found?

Yes


No
  • Test Complete.