Diagnostic Instructions
DTC Descriptor
DTC P0218: Transmission Fluid Overtemperature
Circuit/System Description
Transmission fluid is drawn from the bottom pan through the filter, case assembly, channel plate assembly, control valve body assembly and into the oil pump assembly. The pump is mounted on the control valve body assembly. Fluid pressure leaving the pump
is controlled by the pressure regulator valve and becomes the main supply of line pressure to the various components and hydraulic circuits. Hot fluid from the torque converter flows through the torque converter clutch (TCC) control valve into the cooler
lines to the oil cooler located in the vehicle radiator and auxiliary cooler, if equipped. Cool fluid then returns to lubricate the final drive assembly and other components along the output shaft.
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 130°C (266°F) for 10 minutes.
Action Taken When the DTC Sets
• | DTC P0218 is a type C DTC. |
• | The transmission control module (TCM) freezes transmission adaptive functions. |
Conditions for Clearing the DTC
DTC P0218 is a type C DTC.
Diagnostic Aids
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
Electrical Information Reference
Scan Tool Reference
DTC Type Reference
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.
Ensure that the transmission fluid temperature is 129°C (264°F) or less for 5 seconds.