Light Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human-Machine Interface
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance
Equipment / Tooling; Procedure
Took off out of SJC 30L on the SJC2 Departure as filed; SJC2-MOONY-SJC. Everything normal until before reaching MOONY; the plane appeared to do a smart turn towards SJC; Controller said appeared to be 20 miles before the fix. We asked if we needed to turn back; he said no; just give a good rate to 12000 feet. We were already at 11000 feet.Appeared the next leg activated early and we didn't catch it until ATC asked us why we were turning early. I guess it felt normal because we had done the LOUPE Departure which turns at a similar time.
Air taxi Captain reported ATC question an early turn on departure from SJC.