Car won't start by key but, will start if I jump the starter with screwdriver why?

If you have an automatic transmission you need to check the neutral safety switch; if it's a manual check the clutch safety switch.

Glad you solved it.

wont crank or wont start.??
no car starts , if it cant crank. (unless push starter (M/T magic)
that is not a trans sensor its the PRN switch.
ill answer for, wont CRANK !
it wont crank even with a good battery (charged) or jump started.
1: bad start
2: bad wires to same.
so hot wire the starter small wire, the key start line is tiny.
cranks. , starter good, no crank starter bad or cables bad.
if it cranks hot wired, then the key line is dead.
easy, huh?

U might have 12 volts but no cranking amps try a jump start

Are you saying the engine cranks but won't start, or the engine won't crank ?
If the engine does not crank, you would check for voltage at the starter, the neutral safety switch, and the key switch as well as the ground connections.

need to replace the starter

will it start with a jump ? if it does replace the battery and have the charging system tested, if it will not start with a jump then most likely you will need to replace the starter.

Safety first!--Make sure you're in park & brake on-- Try shorting across the starter terminals with a screwdriver,if the bendix kicks in & nothing spins,remove the starter & put in bench vice ,(or hold down securely), & jump with cables.--REMEMBER POLARITY--If the starter spins you are in deep *******---something in the motor is probably locked up.(If the starter doesn't spin get a new one.)

The 'Keyless Entry & Burglar Alarm System" is activated. You must 'Disarm' the system using the Keyless Entry Remove (Key Fob) to "Reset" the system. The reason the engine won't start is due to the burglar alarm - it has a "Starter Kill" circuit which is activated when the alarm is activated. The alarm must be DEactivated to DEactivate the 'Starter Kill' circuit.
Another way to start the engine is to get in the car, put the key in the ignition and turn it to 'ON" and wait 3 to 5 minutes until the emergency flashers stop/turn off. Afterward, you should be able to start the engine. NOTE: This does NOT reset the burglar alarm. It will go off again when you enter the vehicle without using the remote/key fob.

Ignition relay or fuse could be the problem. When you turn the key to start do you hear a fuel pump kicking on and or do you have spark when you hot wire the starter (I know it's hard to check while trying to start it)? You can email me back and I might be able to pinpoint it more.