PC-12NG pilot reported a pressurization failure resulted in an expeditious descent and diversion to a safe landing.

Narrative

Event SummaryCruise at FL290 established ~32 min after departure.At 1:22 flight time: Yellow CAS 'ACS Low Inflow.'Per POH; ACS bleed air switch ON.Cabin altitude began climbing >10;000 ft ' Red CAS 'Cabin Altitude.'Actions TakenBegan rapid descent and notified ATC after frequency change.Occupants donned oxygen masks.Descended to 11;000 ft within 7 minutes.Attempted POH procedures (auto ' manual pressure control) without effect. Cabin normalized only after descent.Requested diversion and landed ZZZ.ATC tagged flight as priority due to restricted airspace penetration; phone call made to ATC on ground to confirm safe outcome.Maintenance / ContinuationConsulted maintenance; advised attempt continuation at lower altitude.Departed ZZZ. At 8;600 ft climb; ACS Low Inflow re-appeared.Requested level at 9;000 ft; diverted to ZZZ1.Landed without incident. Dumped cabin pressure per POH.Passengers re-accommodated commercially. Aircraft and pilot remained for troubleshooting.OutcomeNo injuries.Safe landings at ZZZ and ZZZ1.Maintenance follow-up in progress.