check engine light won’t go out

I was installing the Shock Therapy front sway bar and disconnected the wiring harness to the front differential. Moved the rzr into the shed for the night and when I backed it out to finish the install I noticed the check engine light on.
The error code on the speedo is 520207 which is AWD control circuit. Reconnected the harness but the check engine light will not go out. How do I clear the system to make the warning light go out.