I have an 02 Silverado LS 4x4. When I close the door the yellow security light stays solid. When this happens it will drain the battery in two days. Also With the key in the on position, either running or not, the air bag light stays on, the ABS light stays on. The Security light, Battery light, Service 4WD, and Low Fuel lights will cycle on and off the this order. The fuel gauge does not work and the Temp gauge does not work.

The truck runs fine, cranks fine, and all other accessories work. If I plan on letting the truck sit for more than a day I have to disconnect battery.

What codes do you have in any of the computers. It sounds like a BCM might be bad. Communication codes might set with this.

Had it scanned for codes at NAPA and it came back with a ignition sensor code. I'm in the process of replacing the ignition housing and the switch now. It'* a slow process for me as I have work going on too. Thanks for your response.