Fiesta 2012 with error codes P0805 amd P0700

[KBarlow]

Hi all, my grandson has a 2012 Fiesta as a first car and it has gearbox issues and shows the MIL and error codes P0805 & P0700. Using Forscan the car completes the diagnostics with no errors, (all adaptive resets, clutch etc) and will clear the codes and then may drive for a while with no problems and generally drives nicely. Other times as soon as you turn on the key the engine light comes on with the associated codes. Often the car refuses to start but repeated cycles of the ignition will sometimes get it to start. From my research it appears to point to the TCM so I am just looking for some guidance to support this before I invest in an aftermarket TCM since Ford have such a long back order. Any assistance greatly appreciated