Calibrate AHRS/mag error g1000

[M20TN_Driver]

So I have gotten this error once before. Wondering if anyone has the procedure they could send me to calibrate. I think it involves some keystrokes to get into the right pages and then, ideally sitting on a compass rose, etc. I’d prefer not to pay a shop if there is a way to do this myself. Thx.  

[N201MKTurbo]

You need to get the install manual and follow the procedures in there.

[AVDB]

From Maintenance Manual:
"Select the GRS/GMU Calibration page and enter the following softkey password:
a) 9
b) 10
c) 11
d) 12 (Far Right softkey)"

During calibration, taxi the aircraft in a good BIG nice circle - you will get smooth and precise taxiing
 

G1000 Magnetometer calibration.pdf

[Schllc]

That’s also the message you get when your magnetometer  has failed. 
 

[M20TN_Driver]

Turned the plane on today and the error was gone.  No clue why.  The local avionics guy was saying that I likely have a loose connection.  Does anyone know where this thing is wired and how?  I'd like to minimally try to put eyes on the unit and its main wiring harness.

Thank you!