Here are the likely culprits and how to troubleshoot them:
* The Passlock System (VATS): This is the most common cause of starting problems in this era of GM cars. The Passlock system uses a resistor in your ignition key that communicates with the car's computer. If the resistor is faulty (due to a worn key, damaged ignition switch, or a bad security module), the car won't start. There's no simple reset. You'll need to:
* Try a spare key: If you have a spare key, try that first. This immediately checks if your key is the problem.
* Check the ignition switch: A faulty ignition switch can prevent the correct signal from being sent. This usually requires professional diagnosis and potentially replacement.
* Have the Passlock system reprogrammed: A locksmith or dealership can often reprogram the system to accept a new key or potentially repair the existing one. This is often the solution. They might need to replace the Passlock module.
* Alarm System: If the car has an aftermarket alarm system, it might be triggered. Check the alarm's manual for instructions on disarming it. Sometimes, a dead battery in the alarm system can cause issues.
* Immobilizer: Similar to Passlock, the immobilizer prevents the car from starting if it doesn't recognize the key. The solution is often the same: key replacement or Passlock system reprogramming.
What NOT to do: There are many unreliable "fixes" circulating online involving bypassing the security system. These are generally unsafe, can damage your car's electrical system, and may even be illegal.
Troubleshooting Steps:
1. Check your car's battery: A weak battery can sometimes cause electrical problems that mimic a security system issue. Get the battery tested.
2. Try all your keys: If you have multiple keys, try each one.
3. Listen for any unusual noises: When you try to start the car, listen carefully for any clicks, whirs, or other unusual sounds. This can help pinpoint the problem.
4. Check the car's computer (OBD-II port): A code reader plugged into the OBD-II port might reveal fault codes that indicate the problem. This can give you more specific information for a mechanic.
5. Consult a professional: If you're not comfortable troubleshooting the car yourself, take it to a qualified mechanic or locksmith who is experienced with older GM vehicles and Passlock systems.
Don't attempt any drastic measures without proper knowledge. Getting a professional diagnosis is often the best and safest approach to fix a starting problem that might seem related to a security system.
