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

The flow of transmission fluid starts in the bottom pan and is drawn through the filter, control valve body assembly, transmission case and into the oil pump assembly. The oil pump assembly pressurizes the fluid and directs it to the pressure regulator valve where it becomes the main supply of fluid to the various components and hydraulic circuits in the transmission. Hot fluid exiting the torque converter flows through the converter clutch apply valve and into the transmission cooler lines to the oil cooler located in the vehicle radiator, and auxiliary cooler if equipped. From the cooler, fluid returns to cool and lubricate the front of the transmission. In forward drive ranges, D4 fluid from the manual valve is routed through an orificed cup plug in the rear of the transmission case to feed the rear lube fluid circuit.

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 136°C (277°F) or greater for 60 seconds.

Action Taken When the DTC Sets

* DTC P0218 is a Type C DTC.
* TRANS 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 TRANS 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.
* Refer to Symptoms - Automatic Transmission (- Symptoms - Automatic Transmission) .

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Transmission General Information (Transmission General 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

Transmission Control Module Scan Tool Information (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 (Testing and Inspection) .

Circuit/System Testing

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 Oil Pressure High or Low (Oil Pressure High or Low) .
* 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 and Filter Replacement (Removal and Replacement) .

* A seized stator in the torque converter-Refer to Torque Converter Diagnosis (Torque Converter Diagnosis) .
* 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.