Since your Airbag light is ON that signifies that there is a problem with the Airbag system..........Now for your tool not communicating with the system it could be the tool is not capable or, you have communication fault with the system................

1) Check all the fuses and wiring to the Module
2) Try any other tool to see if it will communicate with the system

 thats crazy it should commutate

Why its crazy................? as I said before since you have a airbag light staying ON means you have a fault down the line some where.................So, it could be the airbag module faulty, wiring fault or, it could just be a blown fuse........So to be double sure get any other scan tool to see if it will communicate with the system or not if, its not communicating mean you have communication fault which you will have to sort that out first and once you have sort that out than you can see what other faults you have in the system...............