I have a 2001 Toyota 4runner that shuts off as soon as you shift from park. It's an automatic.

SOURCE: transmission problem with 2001 Ford Escort

Sounds like a problem with the shift interlock.Here's how it works:You put your foot on the brake pedal,the brake pedal switch sends voltage to a solenoid mounted on your shifter.The solenoid unlocks the shifter,and you remove it from Park.When the interlock doesnt work,it's usually the interlock solenoid mounted on the shifter malfunctioning,however the brake pedal switch,or wires to and from can also be at fault.

SOURCE: Unable to shift from park into drive

there is a solenoid that releases the shifter when you step on the brake pedal.there is by the shifter a little tab that can be popped out with a small screwdriver,and using your key,put into the hole and the mechanical device will release the shifter.
it is called a shift lock override

SOURCE: 1998 toyota 4runner, **** in transmission

Change your transmission fluid and filter

SOURCE: 2001 Saab 9-3 with automatic transmission will not shift

CHECK BRAKE LIGHT SWITCH FUSE AND BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID FUSE.IF BOTH FUSES ARE GOOD.PROBLEM IS THE BRAKE SWITCH FAULTY OR BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID IS FAULTY.

SOURCE: 2001 Toyota 4runner Limited Alternator belt broke.

simple really 12mm wrench an socket and 14 mm wrench an socket. lossen alt bracket 14mm then tesioner 12mm slide back drop belt and reverse. unless condensioner belt in way then dro 12 mm bolts on shiled then back off 12mm bolts on condensioner pulley remove belt follow previous instructions