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 information to control Torque Converter Clutch (TCC) apply and release, line pressure, and shift timing. The TFT range is -40° to +151°C (-40° 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 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 disables shift adapts.

^ The PCM does not illuminate the Malfunction Indicator Lamp (MIL).

Conditions for Clearing the DTC

^ A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.

^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition 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 problem.

3. This step inspects or repairs the following items:

Engine: Refer to Cooling System and Radiator.

Vehicle: Was the vehicle used to tow excessive weight?

Fluid: Refer to Fluid Level Inspection. Testing and Inspection

Filter: Replace the filter if the filter is cracked or not seated. Refer to Bottom Pan and Filter Disassemble in Unit Repair.

Scavenger Screens: Refer to Unit Repair.

Low Line Pressure: Inspect cooler lines for any crimps or restrictions. Refer to Line Pressure Check Procedure.

Radiator: Refer to Cooling System and Radiator.