2007 Commander XK Factory Service Manual 21 - TRANSMISSION AND TRANSFER CASE

P0710-TRANSMISSION TEMPERATURE SENSOR CIRCUIT





For a complete wiring diagram Refer to Section 8W

Theory of Operation


The Electrohydraulic Control Unit Assembly of the NAG1 transmission contains a temperature sensor to monitor the transmission oil temperature. This sensor is wired in series with the transmission Park/Neutral switch. The Transmission Control Module (TCM) expects to see a valid voltage level from the sensor when the shifter is in Reverse or any forward Drive position. The TCM also expects to see an open circuit condition when the shifter is in the Park or Neutral position. When the controller detects an open circuit when in Reverse or any forward drive position the DTC will set. Note: Due to a open circuit condition in Park or Neutral, the TCM substitutes the Transmission Temperature reading with Engine Temperature when in Park or Neutral



Possible Causes
  
SHIFT LEVER ASSEMBLY OUT OF ADJUSTMENT
  
(T54) TEMPERATURE SENSOR-P/N SWITCH SIGNAL CIRCUIT OPEN
  
(T54) TEMPERATURE SENSOR-P/N SWITCH SIGNAL CIRCUIT SHORT TO VOLTAGE
  
(T54) TEMPERATURE SENSOR-P/N SWITCH SIGNAL CIRCUIT SHORT TO OTHER CIRCUITS
  
(T54) TEMPERATURE SENSOR-P/N SWITCH SIGNAL CIRCUIT SHORT TO ANOTHER CIRCUIT(S)
  
SHIFT LEVER ASSEMBLY
  
TRANSMISSION CONTROL MODULE
  

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)



Diagnostic Test

1. CHECK IF SPEED SENSOR DTCS ARE PRESENT

With the scan tool, read Transmission DTCs.

Are there any speed sensor DTCs present also?

Yes


No

2. CHECK IF SHIFT LEVER ASSEMBLY SHIFT CABLE IS OUT OF ADJUSTMENT

Check the Shift Lever Assembly Cable for proper adjustment per the Service Information. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1/GEAR SHIFT CABLE - ADJUSTMENTS)

Is the Shift Lever Assembly shift cable properly adjusted?

Yes


No

3. CHECK IF ENGINE STARTS IN PARK OR NEUTRAL

Attempt to start the engine in Park or Neutral.

Does the engine start in either Park or Neutral?

Yes


No

4. TRANSMISSION TEMPERATURE SENSOR-P/N SWITCH



Turn the ignition off to the lock position.
Disconnect the TCM C2 harness connector.
Place the gear selector in Drive.
Measure the resistance of the Transmission Temperature Sensor between the (T54) Temperature Sensor-P/N Switch Signal circuit and the (T13) Sensor Ground circuit in the TCM C2 harness connector.

Is the resistance between 500 to 2500 ohms?

Yes


No

5. CHECK THE TRANSMISSION TEMPERATURE SENSOR-P/N SWITCH

Turn the ignition off to the lock position.
Reconnect the TCM C2 harness connector.
Disconnect the Electrohydraulic Control Unit Assembly harness connector.

NOTE: This procedure may set various DTCs to multiple modules connected to the CAN bus. Disregard and erase any DTCs that may set after completion of this procedure.


With the Shift Lever in the Park position, attempt to start the engine.

Does the engine start?

Yes


No

6. CHECK IF THE (T54) TEMPERATURE SENSOR-P/N SWITCH SIGNAL CIRCUIT IS SHORTED TO GROUND



Turn the ignition off to the lock position.
Reconnect the Electrohydraulic Control Unit Assembly harness connector.
Disconnect the TCM C1 and C2 harness connectors.
Measure the resistance between ground and the (T54) Temperature Sensor-P/N Switch Signal circuit.

Is the resistance below 5.0 ohms?

Yes


No

7. CHECK IF (T54) TEMPERATURE SENSOR-P/N SWITCH SIGNAL CIRCUIT IS SHORTED TO ANOTHER CIRCUIT(S)



Measure the resistance between the (T54) Temperature Sensor-P/N Switch Signal circuit and all other circuits in the TCM C1 and C2 harness connectors.

Is the resistance below 5.0 ohms between the (T54) Temperature Sensor-P/N Switch Signal circuit and any other circuit(s)?

Yes


No