P0218

Circuit Description
The automatic transmission fluid temperature (TFT) sensor is a negative coefficient thermistor. When the transmission fluid is cold, the sensor resistance is high. As the transmission fluid warms up, the sensor resistance becomes lower. The powertrain control module (PCM) uses TFT sensor information to control torque converter clutch (TCC) apply and release, line pressure and shift timing. The TFT range is -40°C to +151°C (-40°F to +304°F).
If the PCM detects a high transmission fluid temperature for an extended period of time on the TFT sensor circuit, then DTC P0218 sets. DTC P0218 is a type D DTC.

Conditions for Setting the DTC
^ No TFT sensor DTCs P0711, P0712 or P0713 are set.
^ The transmission fluid temperature is greater than 130°C (266°F) for 10 minutes.

Action Taken When the DTC Sets
^ The PCM does pot illuminate the Malfunction Indicator Lamp (MIL).
^ The PCM freezes shift adapts.
^ The PCM stores DTC P0218 in PCM history.

Conditions for Clearing the DTC
^ A scan tool clears the DTC from the PCM history.
^ The PCM clears the DTC from the PCM history if the vehicle completes 40 consecutive warm-up cycles without an emission related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
^ Inspect the transmission cooling system for possible blockage and restrictions.
^ Inspect the transmission fluid level.

Test Description
The numbers below refer to the step numbers on the diagnostic table:
2. This step ensures that the transmission fluid is at the proper level. A low fluid level may cause an overtemperature condition.
3. This step inspects or repairs the following items:
^ Engine: refer to Engine Cooling.
^ Vehicle: has the vehicle towed excessive weight?
^ Fluid: refer to the Transmission Fluid Checking Procedure.
^ Filter: replace the filter if the filter is cracked or unseated.
Refer to Oil Filter and Seal Replacement (3.5L Twin Cam V6 LX5).
^ Low Line Pressure: Inspect the cooler lines for any crimps or restrictions.
Refer to the Line Pressure Check Procedure.
^ Radiator: Refer to Engine Cooling.