Circuit/System Description
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The control solenoid (w/body and TCM) valve assembly has a built-in TCM temperature sensor to detect overtemperature conditions and is not serviced separately. TCM power will produce heat that is absorbed by the internal heat sink. As long as the heat sink and the controller base plate stay below 142°C (288°F), the TCM will stay operational (no overtemperature shut down). This fault indicates the TCM is in an overtemperature condition and the TCM has shut down to protect it from possible heat damage. The TCM will remain off until the overtemperature condition no longer exists.