Module - Transmission Control: Description
WARNING: This page is about a different car, the 2007 Mitsubishi Raider. However, it is still accessible from the selected car via links, so may be relevant.
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
The Transmission Control Module (TCM) is a sub-module within the Powertrain Control Module (PCM) (1). The PCM is attached to the right-inner corner of the engine compartment.