Security Light Flashing on Message Center

[shambles]

Hello,

I recently acquired a 1999 Silverado Z71. The Security Light Flashes on the Message center when I open the door. Once I start the truck the light goes out. I tried the "re-learning" process...turn the truck on (but don't start) and let it set for 10-15 minutes, but the light still flashes. It still starts and runs fine.

Also the key fob doesn't unlock the Driver door, just the passenger door. I thought Maybe the button cell battery in the key fob was dead, so I replaced it. But didn't fix that issue. I have to use the key to unlock the driver door.

Any suggestions on what is causing the Security Light to flash?