The Passlock system is notorious for failing. There are 3 different parts of this system that can shut down the car and activate the Antitheft security system. The problem will be one of these 3 things. The key. the ignition lock cylinder, or the TDM. The easiest one is the key. The key will either have a small black chip in the key shaft or a transponder hidden in the key head. If there is a chip, they are known for wearing down and not reading correctly. Try wiggling it, cleaning the chip with alcohol, and taking all other keys off the key chain because it pulls on the key and causes problems. If you have no chip and instead a transponded key, (it will have a little "+" sign by the plastic) you can try performing a relearn procedure. It goes like this.
1. Perform a security system relearn.
2. Let the vehicle sit for more than 10 minutes with the key off.
3. Attempt to start the engine, leave the key in the run position monitoring the security system indicator.
4. After 10 minutes, the security indicator will change state.
5. Turn the key off and wait 10 seconds.
6. Attempt to start the engine. If the engine stalls, wait another 10 minutes with the key on.
7. After the second 10 minute timer has expired, turn the key off for 10 seconds.
8. Attempt to start the engine. If the engine stalls, wait another 10 minutes with the key on.
9. After the 3rd 10 minute timer has expired, shut the key off for 10 seconds.
10. The security system will relearn on the 4th starting attempt and the engine should start and run.
If that doesnt work, you will need to start replacing parts. Like i said, there are 3 parts. The key, the ignition lock cylinder, and the Theft Deterrent Module (TDM). all of these are involved in the Passlock system and could be responsible for shutting down the vehicle. And trust me they are all expensive. I always share this link for this problem because there is so much information on there and will be helpful no matter what you decide to do. If all else fails, there is PERMANENT FIX for this problem. You can bypass all aspects of the system and never worry again. That is also on this link.