I bought the ALS 619 in order to read the ABS and Airbag / restraint system on my 2000 silverado. There is no menu choice to read the ABS system. Why?

Also, if I try to read the Restraint / airbag system after entering the 5th VIN digit as the manual says, I get a message saying that the unit is not connecting to the module. If i enter a different digit from the choice list, the ALS 619 unit communicates with the truck and then says no trouble codes present. Any ideas on with whats going on?
At this point I am not far from putting it back in the box it came in and sending it back where it came from; it only arrived about 2 hours ago and I am already having doubts about the value of this unit.