If i push my 4 wheel drive button it won't change. It stays in 2 high. Why? on 2000 GMC Yukon

The lights on the button selector are lit but when I push 4 high or low it stays in 2 high. Any ideas what to check? thanks

1 answer
Cannot be nothing other than a guess in this forum. Recommend you get it to a good honest technician on that one. Here are some the things that are possibly causing problem. Not a extremly tought diagnosis for many techs.

Axle Actuator Ground
Front Axle Actuator Power
Front Axle Actuator Wiring
Front Differential
Transfer Case Control Module (TCCM)
Transfer Case Control Module (TCCM) Connector