Q: Anti-theft system issues after leaving key in overnight. Car won't start.

asked by on

2006 Buick Lucerne won't start. Keys were left in over night. Has gas and battery is fine all lights come on. Security light Flashes for 10 seconds then shuts off. Horn won't work neither will the panic button so I'm assuming it's the anti-theft system.

My car has 40000 miles.
My car has an automatic transmission.

Hello. From what you describe it would appear that your security system may be activated and needs to be reset. This likely happened as a result of leaving the keys in the vehicle overnight. The procedure for resetting the security system is as follows. If this procedure does not reset the system then it may be possible that the system will need to be reset by a GM factory scan tool, requiring a visit to the dealership.

Reset procedure for GM Passkey III Security Systems:

  1. Insert the master key with the black head into the ignition lock cylinder

  2. Turn the key to ON but do not start the engine. The SECURITY light will turn on and stay on.

  3. Wait 10 minutes or until the SECURITY light to turn off.

  4. Turn the key to OFF for 5 seconds.

  5. Turn the key to ON but do not start the engine. The SECURITY light will turn on and stay on.

  6. Wait 10 minutes or until the SECURITY light to turn off.

  7. Turn the key to OFF for 5 seconds.

  8. Turn the key to ON but do not start the engine. The SECURITY light will turn on and stay on.

  9. Wait 10 minutes or until the SECURITY light to turn off.

  10. Turn the key to OFF. The key transponder will be learned on the next start cycle.

  11. Start the vehicle. If it starts and runs normally, the relearn is complete. If you need to program additional keys,

  12. Turn the key to OFF.

  13. Insert the next key. Turn it to ON within 10 seconds of removing the previously used key.

  14. Wait for the SECURITY light to turn off. That may happen quickly. You may not even notice it.

  15. Repeat steps 12 through 14 for all additional keys.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Anti-theft system issues after leaving key in overnight. Car won't start.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: BMW 650i 2006 started acting up: sometimes the AC doesn't blow cold air and the hot engine sign comes on.

Hi There, Overheating with the AC on is generally caused by a couple of possibilities. When the AC compressor is beginning to fail, this may incur an increased load on the motor as it works harder than usual to turn...

Q: Car was running rough, so I figured out it was a faulty ICM. Changed that, now car won't even start.

Hello, thank you for writing in. With the new module you installed, there is likely some other issue with an input to the computer. Either that or the computer itself is having issues. You can only test the computer by...

Q: What can I do to get my car running? It tries to crank and start but it struggles.

If the car is cranking strong with the new starter, and just won't fire up, it's time to re-check the basics. Check for a good spark at the plugs. If spark is good, try spraying a bit of starter fluid...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.