Here are some possibilities, and what you need to do to troubleshoot:
* Factory Immobilizer System (most likely): This is integrated into the car's computer. If you're having trouble starting, it's almost certainly this. The solution is usually to use the correct key. If you've lost your keys, you'll need to have a new key programmed at a dealership or a locksmith specializing in car keys. There's no "reset" in the usual sense; it's about getting the right key recognized by the car's computer.
* Aftermarket Security System: This is an add-on alarm system. These often have a key fob with a reset button or a specific code to disarm it. Consult the owner's manual for the specific system (if you have it). The manual will usually include instructions on disarming or resetting the system.
* Lost Key or Incorrect Key: If you are using the wrong key, the security system will activate. Check for another key, or get a new key programmed as mentioned above.
What to do:
1. Check your owner's manual: This is the first and most important step. Look for sections on the security system, alarm system, or immobilizer.
2. Try all your keys: Make sure you're using the correct key. Sometimes a key can get damaged and not be properly recognized.
3. Listen for alarm sounds: The way an aftermarket alarm sounds, or its behavior when the key is used, could provide clues.
4. Check for an aftermarket system control box: Look under the dashboard or in other hidden locations for a small control box with buttons or switches. This could offer a reset function.
5. If all else fails, contact a locksmith or a Pontiac dealership: They have specialized equipment to diagnose and reprogram your vehicle's security system. They'll be able to help identify which system you have, and find the problem.
Without knowing the specific type of security system in your Pontiac Bonneville, giving a more precise answer is impossible. Providing the year of your Bonneville would help narrow things down.
