truck stuck in auto 4wd changed switch and still stuck any suggestions? on 2005 Chevrolet Silverado 1500

my service 4wd light came on while truck was in 2wd the truck then switched to auto 4wd on its own and the switch still wont work ive checked all the wires in transfer case and changed the switch it still wont do anything ive heard its the encoder motor or the module or the wiring harness i dont wanna spend tons of money and buy the wrong parts i need help please!?

scan for codes and post so we can adv
Qualified Local Chevrolet Shops
Qualified Chevrolet Shops For This Repair
921 N Parker St
RepairPal Shop Scorecard
Technical Ability
Tools & Equipment
Customer Service
Customer Amenities
(714) 486-0367