Four wheel drive engagement

[MC15]

I have a 2012 SCREW w 171k miles. I’m having a four wheel drive issue. Today I put it into 4-wheel high and then couldn’t get it back to 2-wheel unless I shut the truck off. After work I came back and tried to engage 4-wheel high and could not. I could get into 4-wheel low, but not 4-wheel high. The maintenance wrench showed up on the dash.
Any ideas?

 

[Nex]

What is the code?

 

[MC15]

Does not give me a code. Just the wrench.

 

[Nex]

..... use forscan and look for codes. They will not display on the dash.

 

[MC15]

I’ll get back to you.