1999 CHEVY LUNINA WON'T START BATTERY AND

Check the dash once you turn the key to the run position the passlock runs a security check using a set resistance value through the chip in the key. If the security light begins to flash the reading it received was incorrect or it didn't get a reading at all. You can try reseting the value it is looking for by turning the key to start then releasing it. After 10 minutes turn it off then cycle it start again leaving it in on for 10 minutes then back to off then one more time. After the third cycle has completed for a total of 30 minutes. You should be able to turn the key on and start the vehicle. If the light continues to flash their is a problem with the chip in the key or the connections within the ignition its self. Both are common but a Pass Lock Relearn as described above will usually adapt to the poor connection values. Hope this helps.