Every so often(Usually when climbing in to IMC), pressing the AP or EFIS button to engage the autopilot will result in the plane pulling off in some wild direction, like it wants to kill me-and the heading and altitude bug are set appropriately. I immediately disengage and re-boot once or twice and it will then work normally. I am very careful to boot it up on the ground with full GPS signal and airplane stationary. Pitot and static lines are both operating normally. Any words of wisdom? Do I need to send it in for service?

Ted Chipps
N498EC RV-10