About twice a week my 1998 Buick Riviera wont start & I have to wait for the security light to go off.?

The security light takes 2 to 3 minutes to go off %26amp; sometimes it does it twice in a row, so I'm sitting there up to 6 minutes waiting for the security light to go off so I can start the car. I had the key tested by Buick %26amp; they said it was fine. It does it so much I leave the car running if I am just going into the gas station or garage sales so I don't have to worry about it. Any ideas on what the problem is? Thanks!About twice a week my 1998 Buick Riviera wont start %26amp; I have to wait for the security light to go off.?this is the pass key module starting to fail not to many shops know how to fix these i used to repair them and they are hidden in the vehicle randomly so there is no one place they all are, your best be is to take to the dealers they have the tools to test the system some Private shops do but they will all say bring it in but they will not be able to help you and charge you for there time so best be Dealer and the next step in this will be the light will stay on and it will not start till its fixed and is a great GM Theft deterrents but no to much is known in the privet sector, , and see you key has a chip in it and its not giving the correct code to the module (pass key Module small black box under dash above heater core in very different spots in all vehicles, even the dealer will get the location spot from the factory,) you don't half to go to Buick just a Good GM dealer where someone knows about the pas key module