first off i would like to say unless you have had experience with these trucks your diagnosis most likely is incorrect on the TMM card issue , that is unless its burned or something.

Also that TMM card assy comes in 3 parts, the power distribution board, the power supply and the logic unit. You can replace the whole thing if you like but that is an expensive replacement. Also you will need to know what software version in the TMM you have(if you replace the whole assy or replace the logic card), provide battery voltage, a truck model and serial number when ordering, there should also be a tag on the TMM assy with numbers on it. The software version can be obtained by accessing the system and scrolling to the correct menu.

on the control handle , they do offer reman control handles that are slightly less costly than the OEM new.