2010 Cadillac Truck SRX AWD V6-3.0L Page 1294
6T70/6T75 - Automatic Transmission
DTC P0218
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC P0218
- Transmission Fluid Overtemperature
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 (TFT) sensor is located in the control solenoid valve assembly.
Conditions for Running the DTC
* The ignition voltage is 8.6 volts or greater.
* The TFT is -39 to +149掳C (-38 to +300掳F) for 5 seconds.
Conditions for Setting the DTC
The TFT is 140掳C (284掳F) or greater for 1 minute.
Action Taken When the DTC Sets
DTC P0218 is a Type C DTC.
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掳C (270掳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 (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Diagrams)
* Park - Engine Running (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and Operation/6T70/6T75 -
Automatic Transmission/Park - Engine Running)
* Fluid Passages (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and Operation/6T70/6T75 - Automatic
Transmission/Fluid Passages)
Description and Operation
* Transmission General Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and
Operation/6T70/6T75 - Automatic Transmission/Transmission General Description)
* Transmission Indicators and Messages (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and
Operation/6T70/6T75 - Automatic Transmission/Transmission Indicators and Messages)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
