التشغيل ممنوع على ارتفاع عالٍ

A function withheld because the vehicle is operating above the altitude it was calibrated for. Air density falls with altitude, and systems that depend on it — fuel-fired heaters, some regeneration strategies, forced induction limits — are inhibited rather than run outside their envelope.

A fuel-fired auxiliary heater is the clearest case: combustion becomes unreliable in thin air, so the unit refuses to start above a threshold and stores a code. It is designed behaviour and not a fault, which is worth telling an owner who has just driven over a mountain pass. Check the barometric reading in the freeze frame — a code stored at high altitude and never repeated at sea level is the inhibit, and no component needs testing.