P0218

DTC P0218

DTC Descriptor
DTC P0218
- Transmission Fluid Overtemperature

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

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°C (-38°F) and 149°C (300°F) for 5 seconds.

Conditions for Setting the DTC

The transmission fluid temperature is greater than 140°C (286°F) for 1 minute.

Action Taken When the DTC Sets

* DTC P0218 is a Type C DTC.
* The 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
* Automatic Transmission Inline 20-Way Connector End View
* Automatic Transmission Internal Connector End Views
* Automatic Transmission Related Connector End Views

Electrical Information Reference
* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs

Scan Tool Reference
* Scan Tool Data List
* Scan Tool Data Definitions
* Scan Tool Output Controls

DTC Type Reference
* Diagnostic Trouble Code (DTC) Type Definitions
* Diagnostic Trouble Code (DTC) List/Type

Circuit/System Verification

Ensure that the transmission fluid level is at the proper level by perfoming the Transmission Fluid Checking. Testing and Inspection

Circuit/System Testing

1. Perform the Transmission Fluid Checking. 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. If the line pressure is low, refer to Incorrect Line Pressure. Line Pressure Check Procedure
* 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.
- Plugged, kinked or damaged transmission cooler pipes. Refer to Automatic Transmission Oil Cooler Flushing and Flow Test (J35944-A) Automatic Transmission Oil Cooler Flushing and Flow Test (J35944-A) Automatic Transmission Oil Cooler Flushing and Flow Test (J45096). Automatic Transmission Oil Cooler Flushing and Flow Test (J-45096)

* 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.

Component Testing

Transmission Fluid Checking

Line Pressure Check

Incorrect Line Pressure

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair. Verification Tests