Circuit/System Description

WARNING: This page is about a different car, the 2012 GMC Yukon, 2012 Chevrolet Tahoe, and 2012 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.

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 lines, 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. 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.