2005 Chev Silverado "Service Air Bag" warning in message center. Ideas?

I have a 2005 Chev Silverado "Service Air Bag" warning in message center. It also alternates with the message "service four wheel drive". I own a body shop and have an OTC computer. It does not,however, have the latest updates to 2005. So any techs that can help. It is an easy 10 points. I have had a couple of collisions of other peoples that were 2005 or newer with the same problem. I sent them of to the dealer and only heard the results of 1. The dealer said it was the seat switch on the drivers side.The switch that indicates someone is in the seat. Ideas?
Also,my 2,4h,and 4low buttons do not light up. As though none are selected. As well,the 4wd will not engage. Possibly two separate problems,but I think it is something common to the warning lights.But what?