2001 sable transmission trouble

My dad has a 2001 Mercury Sable with a 3.0 v6. tonight he pulled into the drive and parked it, went inside for dinner (about 30 mins) when he started the car it rolled about five feet, and the tranny disengaged (no noise or anything strange) now the tranny will not respond at all to the controller, but when the switch is on “drive”, there is a small suction noise coming from around the area of the tranny?? We cant find a vaccum hose thats off but is there anything else to check?? ANY IDEAS ??

Do some basic checking. Make sure the fluid level is at the correct point. Check to make sure the shifter is actually moving the manual shaft on the transmission.

If these are okay, you probably need to have a technician look at the line pressure and diagnosis further.