Automatic Transmission - 2MT70
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
Diagnostic Fault Information
Circuit/System Description
The primary source of heat in the transmission is the drive motor generators. The drive motor generators are cooled by the transmission fluid. Hot fluid exits the drive motor generators and flows to the transmission cooler supply line. The supply line connects to the cooler, which is in front of the radiator. The transmission fluid cooler pipe assembly is equipped with an internal thermostat that opens at 80°C (176°F) for optimum transmission operation and fuel economy. The transmission cooler pipe thermostat is part of the transmission fluid cooler pipe assembly, located near the left side of the radiator and is not serviced separately. From the cooler, the fluid returns through the transmission fluid cooler pipe assembly and enters the lubrication circuits. After lubricating the internal components, the fluid returns to the oil pan. The transmission fluid temperature (TFT) sensor is located in the control solenoid (w/body and TCM) valve assembly and is not serviced separately.
Conditions for Running the DTC
* The TFT is between -50 and +150°C (-58 and +302°F) for 10 seconds.
* The system voltage is 11-18 V.
Conditions for Setting the DTC
The TFT is greater than 135°C (275°F) for 300 seconds.
Action Taken When the DTC Sets
* P0218 is a Type B DTC.
* The TCM freezes transmission adaptive functions.
Conditions for Clearing the DTC
P0218 is a Type B DTC.
Diagnostic Aids
The driver information center (DIC), if equipped, will display 'TRANSMISSION HOT- Idle Engine' when the TFT reaches 135°C (275°F). The TFT parameter 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. Ensure the engine cooling system is functioning normally.
Reference Information
Schematic Reference
Hydraulic Schematics
* Park - Engine Running (Park - Engine Running)
* EVT Mode Reverse (EVT Mode Reverse)
* Reverse - Engine Running (Reverse - Engine Running)
* Neutral - Engine Running (Neutral - Engine Running)
* EVT Mode Low - Engine Running (EVT Mode Low - Engine Running)
* EVT Mode Low - Engine Off (EVT Mode Low - Engine Off)
* Drive Range, First Gear (First Gear)
* Drive Range, Second Gear (Second Gear)
* Drive Range, Third Gear (Third Gear)
* Drive Range - Fourth Gear (Fourth Gear)
* EVT Mode High - From Drive Range 4th Gear (EVT Mode High - From Drive Range 4th Gear)
* Power Off Low Default (Power Off Low Default)
* Power Off High Default (Power Off High Default)
* Fluid Passages (Fluid Passages)
Connector End View Reference
Component Connector End Views (Connector Views)
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)
Special Tools
J 24731 - Tempil Stick
Circuit/System Verification
1. Review the Failure Records 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.
2. Perform the transmission fluid checking procedure. Refer to Transmission Fluid Check (Transmission Fluid Check).
Circuit/System Testing
1. Inspect the transmission cooling system for restrictions or damage.
• If a concern is found, repair or replace the restricted or damaged components as necessary.
2. Perform the Transmission Fluid Cooler Flushing and Flow Test (Transmission Fluid Cooler Flushing and Flow Test).
• If a concern is found, repair or replace the damaged components as necessary.
3. Perform the automatic transmission Line Pressure Check (Line Pressure Check) procedure.
• If a concern is found repair or replace the damaged components as necessary.
4. Inspect the transmission cooler line thermostat for a stuck closed condition.
• If a concern is found repair or replace the damaged components as necessary.
Component Testing
* Perform the Fluid Leak Diagnosis (Fluid Leak Diagnosis).
* Perform the Transmission Fluid Check (Transmission Fluid Check) procedure.
* Perform the Line Pressure Check (Line Pressure Check) procedure.
* Perform the Main Fluid Pump Pressure High or Low (Main Fluid Pump Pressure High or Low) procedure.
* With a hand held infra red thermometer or J 24731 - Tempil Stick , test for the transmission cooler supply line thermostat opening at 80°C (176°F). The transmission cooler supply line temperature should be higher on the transmission side of the thermostat than the cooler side until 80°C (176°F) is reached.
• If the thermostat tests stuck open or closed, replace the transmission cooler supply line assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Repair or replace the automatic transmission cooler or lines as necessary. Refer to Transmission Fluid Auxiliary Cooler Inlet Pipe Replacement (Service and Repair) and Transmission Fluid Auxiliary Cooler Outlet Pipe Replacement (Service and Repair).
Repair Verification
1. With a scan tool, clear the DTCs.
2. Operate the vehicle long enough to ensure the engine has reached normal operating temperature and the TFT has stabilized between 80-98°C (176-208°F).
3. Observe the specific DTC, and ensure DTC P0218 has run and passed.
4. Check for any other DTCs that you have not diagnosed.