94 has the 47RH trans (no electrics), as far as I remember. Only the TPS and PCM control fluid pressure. The TV cable can be adjusted a little to increase the internal fluid pressure, making more positive shifts, or vice verse.
no reverse could be a couple of things.
check the obvious, like fluid level. I know with the 44RE (Jeep) sometimes the front pump will suck air past the gasket, and not engage reverse (due to a fluid pressure drop. Overfilling by a quart would 'band-aid' the issue.
If the OD snap ring breaks, you'll lose OD and reverse.
Valve body loose will cause fluid pressure drop, and major slipping.
Band Adjustments
Pulling it in manual 1 on decel, look for engine braking. If either the low/reverse band is out or the direct clutches in the OD are messed up, you'll have no engine braking in manual 1. They should both not allow you to have any engine braking. If you have drive and OD then the front clutch appears to be working.