2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1945

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1945

DTC P0218

- Transmission Fluid Overtemperature

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 fluid cooler pipe assembly. The transmission fluid cooler pipe assembly

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掳C (176掳F) for optimum transmission operation and fuel economy. The transmission fluid cooler pipe thermostat is part of the

transmission fluid cooler pipe assembly, located near the transmission 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 sensor is located in the control solenoid valve assembly and is not serviced separately.

Conditions for Running the DTC

The transmission fluid temperature is at least -50 (-58掳F) and no more than +150掳C (+302掳F) for 5 seconds.

Conditions for Setting the DTC

The transmission fluid temperature is greater than 135掳C (275掳F) for 300 seconds.

Action Taken When the DTC Sets

* P0218 is a Type B DTC.

* The driver information center may display 'TRANSMISSION HOT - Idle Engine'.

Conditions for Clearing the DTC

P0218 is a Type B DTC.

Diagnostic Aids

* The driver information center will display 'TRANSMISSION HOT- Idle Engine' with an audible chime when the transmission fluid

temperature is greater than 150掳C (302掳F). The message and chime will not turn off until the transmission fluid temperature is less than 150掳

C (302掳F) and the ignition is Off long enough for the TCM to power down.

* Ask about the customer's driving habits, trailer towing, etc.

* Verify the engine cooling system is functioning normally.

* The hybrid powertrain control module will reduce drive motor generator torque at temperatures greater than 160掳C (320掳F). Drive motor

generator torque is reduced to zero if the temperature reaches 190掳C (374掳F).

* Review with the customer their driving habits, trailer towing, etc. Verify the engine cooling system and transmission cooling system is

functioning normally.

Reference Information

Description and Operation

Electronic Component Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and Operation/2ML70 -

Automatic Transmission/Electronic Component Description)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information.

Circuit/System Verification

1. Verify that P0711, P0712, or P0713 is not set.

瀚慖f DTC P0711, P0712, or P0713 is set, Refer to DTC P0711, P0712, or P0713 ( See: P Code Charts/P0711/2ML70 - Automatic

Transmission).

2. Ignition ON, observe the scan tool ECM engine coolant temperature (ECT) parameter in the freeze frame data. The reading should be below

125掳C (257掳F).

瀚慖f the ECT was above 125掳C (257掳F) when the DTC set, refer to Engine Overheating (See: Engine, Cooling and Exhaust/Cooling

System/Testing and Inspection/Symptom Related Diagnostic Procedures/Engine Overheating).

3. Ignition ON, observe the scan tool Trans. Fluid Temp. parameter in the freeze frame data. The reading should be below 135掳C (275掳F).