EMB-505 Captain reported while taxiing to the hold short line; observing the AHRS 1 and 2 Fault white advisory CAS messages. The flight crew returned to the maintenance hangar when the messages did not clear. After maintenance actions; the flight crew taxied back for take off. The flight crew then observed again the AHRS fault messages and this time in addition following yellow AHRS Fail and Yaw Damp CAS messages. The flight crew returned to the hangar and the flight was cancelled.

Narrative

When holding at ILS critical line tower cleared us to taxi to and hold short Runway XX. While taxiing to the hold short we received AHRS 1 and 2 fault white advisory CAS messages. At about the same time we received clearance to takeoff. We continued to taxi believing that these advisory messages would clear as we continued to move away from the large metal hanger that we were holding near while at the ILS critical line. I had experienced heading anomalies near this large metal hanger before. Unfortunately these CAS messages did not clear as we aligned for takeoff. We cancelled the takeoff clearance and taxied off the Runway at Tower's instruction. These two advisories cleared as we taxied back to our maintenance facility. We contacted maintenance and operations. After being re-dispatched and our write-up was signed off by maintenance; we attempted to complete this trip. After again holding at the ILS critical line and after having received hold short instructions; we again received the AHRS fault messages and this time in addition following yellow AHRS Fail and Yaw Damp CAS messages. Before being cleared for takeoff we informed Tower that we needed to return to the ramp because of a maintenance issue. The flight was then cancelled. Crew advisory AHRS fault messages that did not clear while aligning on the Runway for takeoff. Cancelled takeoff clearance. Will not assume advisory AHRS messages will clear in the future. Will not accept a takeoff clearance until advisory messages have cleared.