Q: Security light on car wont start

Try another key if you have one. If the vehicle starts, then the first key is bad. The keys have a transponder in it that the ignition switch reads and allows the car to start. If you do have a second key and it does not start with either, try this relearn procedure:

The Passlock family has two basic relearn procedures—a ten-minute procedure and a thirty-minute procedure. Which one you use depends on the system and what components have been replaced.

The ten-minute procedure involves trying to start the engine. If nothing happens or the engine starts and dies, the security light will be flashing. Wait ten minutes. The flashing light should go off or illuminate without flashing. When it does, turn the ignition off, wait twenty seconds, and then try to start the engine. If it starts and runs, everything is okay. If you get the same result as previously—nothing happens or the engine starts and dies with the security light flashing—wait ten more minutes then see below.

You will now begin the thirty-minute relearn procedure, which is just the ten-minute procedure repeated three times. After turning the ignition off for the third time and waiting for twenty seconds, the engine should start and run. If it doesn’t, there may still be something wrong with the system.

After the learn procedure is completed and the engine is running, the security light may stay on steady for a few minutes and then go off—this is normal. Depending on the system, replacement of key components will necessitate that a relearn procedure be completed.

If this does not work, then your local dealership will have to perform further diagnosis as the ignition lock cylinder, Powertrain Control Module (PCM), Body Control Module (BCM), or Instrument Panel Cluster (IPC) can all be possible causes.