PC-12 pilot reported a landing gear disagree indication while extending landing gear. Pilot used hand pump to extend gear and continued to a safe landing.

Narrative

Upon becoming stabilized on the visual approach for runway XXR into ZZZ airport; the landing gear handle was put into down position. Gear motor became active and after a few seconds; two out of the three gear lights showed a positive; green light; indicating gear was down and locked. However; the left main gear indicator showed a disagreement: a red light over a green light. To me; that meant there was a possibility that the left main gear was not locked in the down position. I cycled the gear handle up and back down to see if the disagreement would clear. With no luck; I elected to go missed and continue in the traffic pattern while working the problem. After a few checklists; cycling the gear handle up and down a few more times; and using the emergency landing gear hand pump; I was certain all three gear structures were down and locked and this was merely an indication problem and not a mechanical issue. ZZZ Tower controller elected to have ARFF (Airport Rescue and Firefighting) trucks present upon the landing. The landing proceeded without issue and I was able to land and taxi off the runway.