1999 chevy silverado, I cant see mileage or what gear im in?

it can be loose wires or the screen is just dead.

These use the 4L60 or 4L80 transmissions. GM has had plenty of issues with these transmissions. 1 - coming out of apparatus and making this gawd aweful grating/grinding noise 2 - the park claw breaking and dropping all the way down to trap while driving. Makes also a grinding noise until you gradual adequate that it catches and won't unlock once more. Good information is they are not as exspensive to rebuild as any other truck transmissions. I do not know if i'd take it to AAMCO since they have a tendency to make use of less expensive components or usual GM materials. I'd keep round for a just right automatic Transmission save and have them rebuild it with excellent aftermarket components. Can be cheaper then getting it executed by GM who just slap a manufacturing unit rebuild in there.

if the two are digital, look in the fuse box for one that has blown.