air bag service light comes on
That means the airbags are not functionable due to a fault in the system. This is not a DIY fix. Take it to a shop.
Check to make sure the wiring under the passenger side seat is in good condition and not disconnected. There should be a wire under there that goes to a sensor in the seat that tells the system if a passenger is in the seat.
Other than an obvious problem there, it will have to go to a shop, as it could be several things (clock spring, short in wiring, or one of many impact sensors) especially if the vehicle has side air bags. It’s pretty common for GM front impact sensors to fail due to corrosion. That was the problem with my 2005 Sierra, but I had to take it to a shop with the appropriate scanner to diagnose the problem.
Good for you. Now go open your manual.
I don’t see this post as helpful, unless it was meant to steer people away from asking questions here.
You’re right, but it’s easy to get frustrated with these posters who type a handful of words and provide no meaningful details (although in this particular case that’s probably less of an issue), so I can understand how people responding are tempted to be snarky.