2005 S60 2.5T AWD - Heat DMM "calibration".

[MarcM]

My DMM motor is apparently shot. Lost heat totally a couple weeks ago. Here in NH... that kind of sucks from Nov to Mar. It's said that it has to go to the dealer to have them calibrate the motor when replaced. I'm seriously considering pulling the motor and manually moving the damper (if testing proves the motor isn't moving the damper) until I can replace it if it is bad. Probably opening case to move gearing to hold said damper open and reinstalling (leaving unplugged).
Do I really have to go to a dealer to have it calibrated when replaced? Read somewhere that it self-calibrates when the car is switched to run and fan is turned on (causing the standard motor / damper moving noises). I'm assuming this is somehow connected to CAN bus and I'll get a code if I leave it unplugged.
Thoughts / opinions?

[MarcM]

I've had no heat since I bought the car about 4 months ago. REALLY cold in single digit temps driving 35 minutes to work. I would get "heat" on occasion... basically just above cabin temp but would go away. I decided to rip it all apart since I had an early day at work and record it ad hoc on my cell phone. Made a video. Don't know WHAT I did, but suddenly I had heat. We'll see if it sticks when I drive to work tomorrow.
Decided to make it a multi-tier "stop when you get to where you want" to help people get to cabin filter, remove glove box, heat motor/controller & identify the 4 motors on the ECC passenger side.
https://youtu.be/nLFvYk6z_4c

[doublebug]

if you have heated seats more often the small module (under the seat) that control seat heat is the culprit.