P2742

P2742-TRANSMISSION FLUID TEMPERATURE SENSOR 2 LOW





For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams


Theory of Operation


The Torque Converter Out Oil Temperature sensor is used to determine if the transmission needs to go into high temperature shift strategy to protect the transmission.



When Monitored:
- Ignition on, 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 (T819) TORQUE CONVERTER OUT OIL 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 Torque Converter Out Oil Temperature sensor harness connector.

Measure the resistance between ground and the (T819) Torque Converter Out Oil Temperature Signal circuit.

Is the resistance below 100k ohms?

Yes

- Repair the (T819) Torque Converter Out Oil Temperature Signal circuit for a short to ground.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test

No

- Go To 3



3. CHECK THE (T819) TORQUE CONVERTER OUT OIL TEMPERATURE SIGNAL CIRCUIT FOR A SHORT TO (T820) SENSOR GROUND CIRCUIT





Disconnect the TCM C3 harness connector.

Measure the resistance between the (T819) Torque Converter Out Oil Temperature Signal circuit and (T820) Sensor Ground circuit in the Torque Converter Out Oil Temperature sensor harness connector.

Is the resistance below 100k ohms?

Yes

- Repair the (T819) Torque Converter Out Oil Temperature Signal circuit for a short to the (T820) Sensor Ground circuit.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test

No

- Go To 4



4. CHECK THE TRANSMISSION TEMPERATURE SENSOR










Turn the ignition off to the lock position.

Reconnect the Torque Converter Out Oil Temperature sensor harness connector.

Disconnect the TCM C2 and C3 harness connector.


NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the Transmission Temperature Sensor between the (T819) Torque Converter Out Oil Temperature Signal circuit in the TCM C2 harness connector and the (T820) Sensor Ground circuit in the TCM C3 harness connector.

Using the chart at the chart above, compare the Torque Converter Out Oil 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

- 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.