No 3rd gear psi switch...what is a down side???

[turbo nasty]

2004r having to change wire harness over to the 4 wire from 3 for my gn.

Now my question is without the 3rd gear sw will my conv lock up while it is manually in third at the chip set MPH??

Does the ECM use the 3rd gear sw for anything other than L/U i.e ignition, fuel??

Thanx

 

[turbo nasty]

TTT