AF40-6 - Automatic Transmission
DTC P0218
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC P0218
- Transmission Fluid Overtemperature
Diagnostic Fault Information
Circuit/System Description
The primary source of heat in the transmission is the torque converter. Hot oil exits the torque converter through the torque converter clutch (TCC) control valve and flows to the transmission cooler supply line. The supply line connects to the cooler, which is in the radiator. From the cooler, the oil returns through the oil cooler return line and enters the lubrication circuits. After lubricating the internal components, the oil returns to the oil pan. The transmission fluid temperature sensor is located in the control solenoid valve assembly.
Conditions for Running the DTC
* The ignition voltage is between 10.2-15.5 V.
* The engine speed is greater than 400 RPM for 2 s.
* The transmission is not in emergency mode.
* Transmission control module (TCM) communication is normal.
Conditions for Setting the DTC
* Vehicle speed less than 180 km/h (112 MPH) and transmission fluid temperature more than 150°C (302°F) for more than 10 s
* Vehicle speed more than 180 km/h (112 MPH) and transmission fluid temperature more than 150°C (302°F) for more than 60 s
Action Taken When the DTC Sets
* DTC P0218 is a Type C DTC.
* Warning message to the driver via CAN bus
Conditions for Clearing the DTC
* DTC P0218 is a Type C DTC.
* Vehicle speed less than 170 km/h (106 MPH) and transmission fluid temperature less than 140°C (284°F) for more than 3 s
* Vehicle speed more than 170 km/h (106 MPH) and transmission fluid temperature less than 140°C (284°F) for more than 3 s
Diagnostic Aids
Ask the customer whether their typical day-to-day driving include:
* Trailer towing
* Trailer towing should occur in D 4th gear.
* Hauling or vehicle overloading
* Hot climate driving
* Extended idling
* Extreme off-road conditions
* Ensure the engine cooling system is functioning normally.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (AF40-6 - Automatic Transmission)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Description and Operation
* Transmission Indicators and Messages (Transmission Indicators and Messages)
* Transmission Component and System Description (Transmission Component and System Description)
* Transmission Overheats (Transmission Overheats)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Verify the transmission fluid level, color and odor is correct.
2. Review the Freeze Frame when the DTC set.
• If the engine coolant temperature (ECT) was above 125°C (257°F) when the DTC set, refer to Engine Overheating (Engine Overheating) and correct that concern first.
Circuit/System Testing
Dynamic Test
1. Inspect the transmission cooling system for restrictions or damage, inducing any auxiliary cooler if equipped.
2. Perform the Transmission Fluid Cooler Flushing and Flow Test to verify proper transmission oil cooler flow.
• If a concern is found, repair or replace the damaged components as necessary.
3. Perform the Line Pressure Check to verify proper transmission line pressure.
• If a concern is found repair or replace the damaged components as necessary.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Transmission Fluid Level and Condition Check (Transmission Fluid Level and Condition Check)
* Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection (Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection)
* Control valve body-Refer to Control Valve Body Replacement (Control Valve Body Replacement).
* TCM-Refer to Control Module References (Programming and Relearning).
* Perform the Transmission Adaptive Functions (Transmission Adaptive Functions).