TBM 940 pilot reported two separate incidents in which the G3000 autopilot initiated an uncontrolled pitch up attitude resulting in an unsafe speed reduction during the initial climb phase.

Narrative

The G3000 autopilot (AP) commanded an extreme pitch up maneuver after activation leading to loss of indicated airspeed and intervention required by the pilot to deactivate the autopilot. This was the second time that it occurred in this aircraft and details are provided below. The aircraft is a TBM 940 model with installed Garmin G3000 avionics with installed factory auto-throttle (AT) functionality. Departed ZZZ airport in clear morning visual conditions in Class E airspace before the tower opened; turning initially southwest towards ZZZ1 VOR to pickup an instrument flight plan from Center.Takeoff was completed normally in standard TO mode; with the AT also in TO mode. On the takeoff roll; due to high OAT; the motor was ITT limited and produced approximately 80% power which was fine for prevailing conditions. Initial climb was normal; gear retracted and flaps up normally; and a manual turn initiated towards ZZZ1 VOR. Climbing 130 knots; the AP was OFF and was configured to climb to 16;000 feet; GPS direct to ZZZ1; AT mode FMS (which is configured for 150 knot en-route climb) and then AP ON. The aircraft proceeded to immediately begin pitching up ultimately to a maximum of 19 degrees and reducing airspeed to a minimum of 105 knots. During the pitch up and slow down; the control-wheel steering (CWS) button was used twice to pitch back down and countermand the behavior before the AP was deactivated and made OFF using the AP OFF button and the climb was flown manually. A report of this unsafe autopilot behavior was made immediately to the manufacturer who begin involving their engineering staff. It was the second occurrence of this specific unsafe behavior that I experienced in this aircraft and the manufacturer encouraged me to look and find the previous flight so they could compare the two events.The previous flight occurred departing ZZZ2 and the autopilot commanded a pitch up ultimately of maximum 21 degrees with a minimum airspeed of 99 knots before intervention with AP OFF. The defined minimum maneuvering speed on this aircraft is 120 knots and no autopilot should ever intentionally pitch up or slow down that much. This is a serious safety issue and needs to be investigated. The manufacturer has indicated that their engineering staff is escalating to Garmin engineering staff; but I am not involved in those communications. Thankfully these two events happened in clear VMC conditions; but I am particularly concerned that this might occur in bad weather or in crowded airspace resulting in loss of separation or loss of control. It is not clear if the underspeed protection in the autopilot would have eventually triggered to prevent a stall.