P0218
DTC P0218
Circuit Description
The transmission fluid pump is constantly circulating fluid through the torque converter. Hot fluid leaving the converter flows through the transmission cooler lines to the oil cooler, located in the vehicle radiator. From the cooler, the fluid returns to the transmission.
Lube 1 fluid flows through the input shaft to lubricate the transmission components in the front of the transmission. The Lube 2 fluid circuit is fed by line pressure at the pressure regulator valve. Lube 2 fluid flows through the oil feed pipes, and into the forward clutch support. Lube 2 fluid provides lubrication to the rear components of the transmission.
When the transmission control module (TCM) detects a high transmission fluid temperature (TFT) for a long period of time, then DTC P0218 sets. DTC P0218 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0218 Transmission Fluid Overtemperature
Conditions for Running the DTC
The transmission fluid temperature (TFT) is between -39°C and 149°C (-38°F and 300°F) for 5 seconds.
Conditions for Setting the DTC
The TFT is greater than 140°C (284°F) for 2 minutes.
Action Taken When the DTC Sets
^ The TCM does not illuminate the malfunction indicator lamp (MIL).
^ The TCM freezes transmission adaptive functions.
^ The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
^ The TCM stores DTC P0218 in TCM history.
Conditions for Clearing the DTC
^ A scan tool can clear the DTC.
^ The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring.
^ The TCM cancels the DTC default actions when the fault no longer exists and the DTC passes.
Diagnostic Aids
Ask the customer about overloading the vehicle, exceeding the trailer-towing limit, or towing in Overdrive.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. This step tests for low fluid level, which can cause high transmission fluid temperatures.
3. This step inspects for transmission cooling restrictions.
