2002 Bravada AWD coming on after getting new tires on front

I have a 2002 Olds Bravada which needed two new tires replaced on front. I had them put on and the tires balanced or whatever they do to them due to the fact that they were only worn on the very inside of the tires, so bad the wires were sticking out. Since then, my AWD service light keeps coming on and off. I called the place where I had my tires put on and they say to take it to a gm shop but I don't want to be out any money if it is a simple fix. Any help or ideas would be appreciated!!! Thanks!!

Are the new tires the same size as the old tires? If they are different sizes that would be your problem.

They are the same size tires that was put on.

They are the same size tires that was put on.

Rule no one on 4W replace all 4tires at one time.
Tires should be replaced with a set of 4 tires same brand and size at the same time.

The only to tell for sure what the problem is to get it put on a transmission/transfer case capable scanner.
Post back code no.

Ayup, it's really better to replace all four tires at the same time on an AWD vehicle. Even though they are the same "size", the new tires will spin just a little slower than the old rear ones because of a difference in the diameters...the new tread will add about 3/4" to the diameter. The AWD is activated when the system detects this difference in spin between the front and back wheels.

The abnormal wear on the inside of the front tires means you need an alignment...hope that's what you meant to say. If you've had to constantly steer left or right, or the truck feels like it wanders in the lane, this means they are out of alignment. Doing this makes sure both front tires are pointing straight ahead when the steering wheel is on center on a flat road. Check your invoice to see if this was done. It is not the same as balancing or rotating the tires. If so, hopefully you're good to go with 2 nrew tires for the rear. Hope this helps!