P0218
DTC P0218
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provide an overview of each diagnostic category.
DTC Descriptors
DTC P0218
- Transmission Fluid Overtemperature
Diagnostic Fault Information
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, the primary source of heat in the transmission, flows through the torque converter clutch (TCC) control valve into the oil cooler supply line. The oil cooler supply line connects to the oil cooler, which is located in the vehicle radiator and auxiliary oil cooler, if equipped. Cool fluid then returns by way of the oil cooler return line to lubricate the final drive assembly and other components along the output shaft. After lubricating the internal components, the oil returns to the oil pan. The TFT sensor, attached to the bottom of the valve body, is part of the internal transmission wire harness and not serviced separately. The normal TFT operating temperature is -40 to +151°C (-40 to +304°F).
Conditions for Running the DTC
* No TFT DTC P0711, P0712, or P0713.
* The ignition voltage is between 8.0 and 18.0 volts.
Conditions for Setting the DTC
The TFT is greater than 140°C (286°F) for 1 minute.
Action Taken When the DTC Sets
* DTC P0218 is a type C DTC.
* The transmission control module (TCM) freezes transmission adaptive functions.
* If equipped, the driver information center (DIC) displays "TRANS HOT - IDLE ENGINE".
Conditions for Clearing the DTC
DTC P0218 is a type C DTC.
Diagnostic Aids
The DIC, if equipped, displays "TRANS HOT - IDLE ENGINE" when the TFT reaches 132°C (270°F). The TFT on the scan tool should rise steadily to a normal operating temperature, and then stabilize. Ask about the customer driving habits, trailer towing, etc. Trailer towing should occur in DRIVE (D). Ensure the engine cooling system is functioning normally.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views
Description and Operation Reference
* Transmission General Description (Transmission General Description)
* Transmission Component and System Description (Transmission Component and System Description)
Electrical Information Reference
* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs
DTC Type Reference
Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Important: Ensure the transmission fluid is at the proper level by performing the Transmission Fluid Check (Testing and Inspection) .
1. Ask about the customer driving habits, trailer towing, etc. Trailer towing should occur in D.
2. Review the Failure Records when the DTC set. Verify the engine coolant temperature is less than 125°C (257°F).
• If greater than the specified value, refer to Engine Overheating .
3. Ensure the engine cooling system is functioning normally/properly. The TFT on the scan tool should rise steadily to a normal operating temperature, and then stabilize.
4. Inspect the transmission cooling system for restrictions or damage.
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
1. Inspect for restricted air flow through the radiator and/or auxiliary cooler, if equipped, due to debris or damaged fins.
• If a concern is found, repair or replace the damaged components as necessary.
2. Inspect the transmission cooling system and/or auxiliary cooler, if equipped, for kinked or damaged transmission cooler lines.
• If a concern is found, repair or replace the damaged components as necessary.
3. Perform the Transmission Fluid Cooler Flushing and Flow Test (J35944-A) (Automatic Transmission Oil Cooler Flushing and Flow Test (J35944-A))Transmission Fluid Cooler Flushing and Flow Test (J45096) (Automatic Transmission Oil Cooler Flushing and Flow Test (J-45096)) to verify proper transmission oil cooler flow.
• If a concern is found, repair or replace the damaged components as necessary.
4. Perform the Line Pressure Check (Line Pressure Check Procedure) to verify proper transmission line pressure.
• If the line pressure is low, refer to Incorrect Line Pressure (Incorrect Line Pressure) .
Component Testing
* Refer to Transmission Fluid Check (Testing and Inspection) .
* Refer to Line Pressure Check (Line Pressure Check Procedure) .
* Refer to Incorrect Line Pressure (Incorrect Line Pressure) .
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.