AS68RC Automatic Transmission

P0712-TRANSMISSION TEMPERATURE SENSOR 1 LOW





For a complete wiring diagram Refer to Diagrams/Electrical.

Theory of Operation


The Transmission Oil Temperature Sensor is used to determine shift schedule selection. Transmission Oil Temperature is also used in TCC operation.


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

- Set Condition:
The DTC will set if the monitored Transmission Temperature Sensor Signal circuit is greater than 200° C (392° F) for more than 500 ms.







Always perform the AS68RC Pre-Diagnostic Troubleshooting procedure before proceeding. AS68RC - Pre-Diagnostic Troubleshooting Procedure


Diagnostic Test


1. CHECK IF DTC IS CURRENT
With the scan tool, view 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 5



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 Assembly C1 harness connector.
Measure the resistance between ground and the (T54) Transmission Temperature Sensor Signal circuit.
Is the resistance above 100k ohms?

Yes


- Go To 3


No


- Repair the (T54) Transmission Temperature Sensor Signal circuit for a short to ground.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test



3. CHECK THE (T54) TRANSMISSION TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO (T820) SENSOR GROUND CIRCUIT




Disconnect the TCM C3 harness connectors.
Measure the resistance between the (T54) Transmission Temperature Sensor Signal circuit and (T820) Sensor Ground circuit in the Transmission Solenoid Assembly C1 harness connector.
Is the resistance above 100k ohms?

Yes


- Go To 4


No


- Repair the (T54) Transmission Temperature Sensor Signal circuit for a short to the (T820) Sensor Ground circuit.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test



4. CHECK THE TRANSMISSION TEMPERATURE SENSOR









Turn the ignition off to the lock position.
Reconnect the Transmission Solenoid harness connector.
Disconnect the TCM C3 harness connector.

NOTE: Check connectors - Clean/repair as necessary

Measure the resistance of the Transmission Temperature Sensor between the (T54) Transmission Temperature Signal circuit and the (T820) Sensor Ground circuit in the TCM C3 harness connector.
Using the chart at the chart above, compare the Temperature Sensor temperature to the correlating resistance value.
Is the resistance within the specified range when the sensor is at the given temperature?

Yes


- Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors 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 TCM.


No


- Remove the Transmission Oil Pan and inspect the internal Transmission harness, pins, terminals, and connectors for corrosion, damage, or terminal push out. If no problems are found, replace the Transmission Temperature Sensor.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test



5. CHECK WIRING AND CONNECTORS
The conditions necessary to set the 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.
Check for any Service Bulletins that may apply.
Were there any problems found?

Yes


- Repair as necessary.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test


No


- Test Complete.