Theory of Operation
WARNING: This page is about a different car, the 2011 RAM Pickup and 2011 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The Transmission Control Module (TCM) performs several internal checks on the processor. The controller checks the Check Sum of the ROM, the Read/Write integrity of the RAM, and the Check Sum of the EEPROM.