Service air bag

my 2007 gmc sierra 6 cyl has a service air bag light on. the serviceman said it may be a sensor. he said that it was not that after testing the new sensor. they are at odds on this matter… help

You will have to have the codes read and then troubleshoot based on that. Was the serviceman doing this. what codes did he get. Sometimes the dealer has better scan capability for airbags/SRS system.

Who are “they”?

In any case we can’t really help as well without the error codes. That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.