Diagnostic Instructions
DTC Descriptor
DTC P0218: Transmission Fluid Overtemperature
Circuit/System Description
The primary source of heat in the transmission is the torque converter. Hot oil exits the torque converter through the torque converter clutch (TCC) control valve and flows to the transmission cooler supply line. The supply line connects to the
cooler, which is located in the radiator. From the cooler, the oil returns through the oil cooler return line and enters the lubrication circuits. After lubricating the internal components, the oil then returns to the oil pan. The oil pump draws oil through
the filter from the oil pan, where the transmission fluid temperature (TFT) sensor is located. The oil pump pressurizes the oil and directs it to the pressure regulator valve. The pressure regulator valve is the starting point for the main supply of oil
to the torque converter and the transmission hydraulic components.
Conditions for Running the DTC
The transmission fluid temperature is between -39 and +149°C (-38 and +300°F) for 5 seconds.
Conditions for Setting the DTC
The transmission fluid temperature is greater than 132°C (266°F) for 10 minutes.
Action Taken When the DTC Sets
• | DTC P0218 is a Type C DTC. |
• | TRANSMISSION HOT - IDLE ENGINE displays on the driver information center (DIC). |
• | The transmission control module (TCM) freezes transmission adaptive functions. |
Conditions for Clearing the DTC
DTC P0218 is a Type C DTC.
Diagnostic Aids
The DIC, if equipped, will display TRANSMISSION HOT - IDLE ENGINE when the transmission fluid temperature reaches 132°C (270°F).
Ask the customer about possible overloading, exceeding the trailer towing limit, or towing in overdrive.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Transmission General Description
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Transmission Control Module Scan Tool Information
Circuit/System Verification
Ensure that the transmission fluid level is at the proper level by performing the
Transmission Fluid Check.
Circuit/System Testing
- Perform the
Transmission Fluid Check.
⇒ | If the level is not within specifications, repair as necessary. |
- Inspect for the following conditions:
• | Transmission fluid flow through cooler and/or auxiliary cooler, if equipped, is restricted due to: |
- | Transmission fluid level low |
• | Air flow through transmission fluid cooler and/or auxiliary cooler, if equipped, is restricted due to: |
• | Engine overheating due to: |
- | Low coolant level--check coolant temperature, coolant level, and hoses |
⇒ | If any of the conditions listed are found, repair as necessary |
Component Testing
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the repair.