1. Check the Obvious:
* Battery: A weak or dying battery can cause all sorts of electrical gremlins, including anti-theft system issues. Start by checking the battery voltage. A fully charged battery should read around 12.6 volts. If it's low, charge it or replace it.
* Key: Make sure you're using the correct key. If you have multiple keys, try each one. If the key fob is malfunctioning (if equipped), replacing the battery in the fob might solve the problem.
* Ignition Switch: A faulty ignition switch can disrupt communication with the anti-theft system. This is a more complex issue and might require professional diagnosis.
2. Dealing with the Passlock System (Most Likely Culprit):
The 1997 Buick Skylark likely uses a Passlock system. This system uses a resistor in the ignition key to communicate with the car's computer. If the system doesn't recognize the key's resistor, it will disable the engine.
* Try Multiple Keys: Again, ensure all keys are tried.
* Key Programming: If none of your keys work, you'll likely need to have the keys reprogrammed. This typically requires a visit to a locksmith experienced with Passlock systems or a Buick dealership. They'll have the equipment to program new keys or reprogram existing ones.
* Passlock Module Failure: In some cases, the Passlock module itself might be faulty. This is a more complex repair requiring diagnostic tools and potentially replacement of the module. A mechanic will need to test the module to confirm this.
3. Other Possible Issues:
* Alarm System: A separate aftermarket alarm system could be interfering. Disconnecting the alarm's battery (temporarily) might help determine if it's the culprit. *Do this cautiously, as some alarms have backup batteries.*
* Security Light: Look for a security light on the dashboard. If it's flashing, it typically indicates a problem with the anti-theft system.
* Computer Issues: Rarely, the car's computer itself might have a fault affecting the anti-theft. This usually requires professional diagnosis with a scan tool.
Important Note: Attempting to bypass the anti-theft system without proper knowledge can damage your car's electronics or lead to further complications. It's strongly recommended to seek professional help from a qualified mechanic or locksmith specializing in Buick vehicles if you can't resolve the issue by checking the battery and keys. They have the diagnostic tools necessary to pinpoint the exact problem and perform the necessary repairs or reprogramming.
