PC-12 First Officer reported a stall warning system malfunction during the initial climb resulting in an intermittent stick shaker. The flight diverted to an alternate airport and landed.

Narrative

While I was performing a short field takeoff on Runway XX at ZZZ we experienced a stall warning and shaker immediately after rotation. The PCL (Power Control Lever) was set in the takeoff power detent and I reduced AOA and increased airspeed at the recognition of the warnings. The entire airspeed tape was highlighted red; shaker was activated; and were hearing the aural stall warning throughout the encounter; despite the increase in over 115 KIAS in the climb. I handed flight controls to Person A during the climb. I contacted ZZZ Approach; requested priority handling; and explained our scenario. We asked for vectors and ran the QRH for inadvertent shaker. Upon completion of the QRH items the red airspeed tape; shaker; and aural warning went away. We were informed from the QRH that the aircraft was no longer stall protected and it was best to proceed back to ZZZ1 due to its long runway; our familiarity with the area; and the maintenance availability at the field. The remainder of the flight went without issue and Person A safely performed a flaps 15 landing back in ZZZ1.