4x4 won't work

[Racermt]

I have a 03 chevy that won't engage into 4 wheel drive, tried it the other day when we got snow and the button just flashes and it says service 4x4 on the dash. I tried switching buttons from my grandpa's 07 classic and no luck. It seems like it's the actuator, I can hear it attempt to engage. Anyone ever have this problem?

 

[smokinVE]

Fairly common for the encoder motor to fail. There could be other problems. Get the codes pulled. Aslo clean and retorque the two grounds by on the drivers side body mount, just forward of the driver door on the back side of the frame where the mount is.