BATTERY DIES WHEN I TURN THE CAR OFF

Are you saying the starter motor won't crank the engine? If so, I'd have to make sure battery has a full charge and battery connections all good. I'd also check the starter motor wiring circuits. Any testing at starter motor, make sure tranny is in park or neutral and parking brake is set.
Now, if it cranks good but won't start, have a helper crank it while you check for spark at the spark plugs, if spark everywhere, use a gage and check proper fuel pressure and fuel injector pulse.
Code 54 should be for the cam sensor in distributor. If I get a code for cam or crank sensor, I usually check them both. I check the wiring circuits.

Hi Teresa thats ththhe sign of a battery going bad, how old is the battery? You might want to have it load tested so you can trouble shoot further, there could be more than 1 issue.

Check to see if the timing belt has broken.

If your engine dosen`t even crank you have to first make sure the battery is fully charged.If so it sounds like it is your starter.When your starter goes bad your engine wont crank you get nothing when you turn the key.Try to start there.

run fault codes and check for cam/crank sensor. check that the cam shaft is turning( broken cam belt) check operation of the immobiliser. Check that the fuel pump is working.

Do the basic tests. If it cranks good but won't start, have a helper crank it while you check for spark at the plugs. If spark everywhere use a gage and check proper fuel pressure and fuel injector pulse.
Any applicable trouble codes?

What is the voltage on the battery ? If it's not in the 13.5 volt range the battery is not charged.
What does the battery read when you try to crank ? It should be in the 10.5volt range.
Get a set of jumper cables. Hook them up correctly and see if it cranks. If it does - the battery is not fully charged or it's a bad battery.
A car battery can produce enough amps to light lights and other small stuff but not produce enough amps for the starter to turn over the engine.

With this tiny bit of info, it is really hard to tell. Will it fire? Will it even turn over? Is it getting fuel? Are the plugs in good shape? Are the plug wires in good shape? I would change the plugs, the plug wires, check to make sure your fuel pump is functioning, and change your fuel filter. Also, if you have an old style cap and rotor distributor, check the copper points. If they are corroded, you need to clean them. If you have a distributor block, you might need to replace a coil. Also, on late model Toyotas, inside the distributor cap, there is an ignition coil. My Toyota Camry 1992 died driving down the road. I changed the ignition coil and had to rotate the distributor cap and it finally started. All things mentioned could be the culprit. Trial and error, I'm afraid, is the best way to go. Start with the cheapest stuff and then progress forward.

What about the distributor?

If it will start right back up and if you hold gas pedal will truck stay running ? if it will stay running when you hold the gas then replace the idle air control valve it is bad and cleaning it didnt help. but if it wont stay running even if you hold the gas pedal then the first thing is to make sure you are not loosing fuel presure