Cant shift out of park

[alc5m]

My dad has a 97 burban, slt trim i believe (if that matters), and it wont shift out of park

When he pushes the brake, the shifter wont move

The truck has 160,000 miles or so, but we're extremely confused on what could cause this problem, or how to fix it. Its happened before, but went away promptly, appears to really only do it in the cold (we live in WI)

any help would be appreciated.

Thanks

i believe its the 4L60E as well

 

[chevy_man]

Mine did that one morning, it was the cable that went to the indicator in the dash.

Or you could have ice buildup on your shift linkage. 0r it could be the brake interlock not functioning