P0218
DTC P0218
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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. 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.
* The TFT is -39 to +149°C (-38 to +300°F) for 5 seconds.
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
* DTC P0218 detects a high transmission fluid temperature for a long period of time.
* 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 (Connector Views)
* Inline Harness Connector End Views (Connector 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 (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Verify the transmission fluid is at the proper level by performing the Transmission Fluid Check (Testing and Inspection).
2. Ask about the customer driving habits, trailer towing, etc. Trailer towing should occur in D.
3. 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 (Engine Overheating).
4. 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.
5. Inspect the transmission cooling system for restrictions or damage.
6. 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.
7. 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.
8. 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.
9. Perform the Transmission Fluid Cooler Flushing and Flow Test (J-35944-A) (Automatic Transmission Oil Cooler Flushing and Flow Test (J35944-A))Transmission Fluid Cooler Flushing and Flow Test (J-45096) (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.
10. 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).
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.