UmmScott

The 36 code is listed in the FSM. It's "ATC CONTROL COMMUNICATION
FAILURE". I've never had that one, but it's been claimed byh some to be a common code even when everything is working fine. If that's true, you can't necessarily read too much into it.

Is the system low on charge? Oh - also - a common problem is for the little cabin air sampling fan in the ATC head unit to get clogged with dust so it can't spin at all - so the system can't tell what the actual temperature is. Blow some compressed air into the slits for that on the left side of the head unit - it might work to blow a big, sudden puff of air into the slits with your mouth - that worked for me.