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) provides an overview of each diagnostic category.
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 2 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
The driver information center (DIC), if equipped, will display 'TRANSMISSION 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's driving habits, trailer towing, etc. Trailer towing should occur in D4. 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)
Description and Operation
Electronic Component Description (Electronic Component Description) for automatic transmission fluid temperature sensor information
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. 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 range, refer to Engine Overheating (Engine Overheating) .
2. Inspect the transmission cooling system for restrictions or damage.
3. Perform the Transmission Fluid Check (Testing and Inspection) to verify correct fluid level and condition.
4. Perform the Transmission Fluid Cooler Flushing and Flow Test (J 45096) (Automatic Transmission Oil Cooler Flushing and Flow Test (J 45096))Transmission Fluid Cooler Flushing and Flow Test (J 35944-A) (Automatic Transmission Oil Cooler Flushing and Flow Test (J 35944-A)) to verify proper transmission oil cooler flow.
5. Perform the Line Pressure Check (Line Pressure Check Procedure) to verify proper transmission line pressure.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Circuit/System Testing
1. Perform the Transmission Fluid Check (Testing and Inspection) .
• If the level is not within specifications, repair as necessary.
2. Inspect for the following conditions:
* Transmission line pressure low-refer to Line Pressure Check (Line Pressure Check Procedure) . If the line pressure is low, refer to High or Low Line Pressure (High or Low Line Pressure) .
* Transmission fluid flow through cooler and/or auxiliary cooler, if equipped, is restricted due to:
- Transmission fluid level low
- A clogged filter
- A leaking filter or seal-refer to Automatic Transmission Fluid Filter and Seal Replacement (Service and Repair) .
- Plugged, kinked or damaged transmission cooler pipes-refer to Transmission Fluid Cooler Flushing and Flow Test (J 45096) (Automatic Transmission Oil Cooler Flushing and Flow Test (J 45096))Transmission Fluid Cooler Flushing and Flow Test (J 35944-A) (Automatic Transmission Oil Cooler Flushing and Flow Test (J 35944-A)) .
* Air flow through transmission fluid cooler and/or auxiliary cooler, if equipped, is restricted due to:
- Damaged fins
- Debris
* Engine overheating due to:
- Low coolant level-check coolant temperature, coolant level, and hoses
- Restricted air flow
- Restricted coolant flow-refer to Engine Overheating (Engine Overheating)
If any of the conditions listed are found, repair as necessary.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.