T-case shift module question

[CHH777]

Anyone know what that little button does on the t-case shift module? When I press it a LED comes on for a minute and then goes out.

 

[Triton46]

Its a diagnostic. There are two harnesses plugged into it, take the harnesses out and push the button.

If the light blinks, you have a problem with the electric motor. If it just stays on, you have a problem with the module. Not sure what it does if all is working correctly.

 

[CHH777]

Thanks Triton.