12257A - SERVICE UPDATE (REVISED SERVICE PROCEDURE). THE NAVIGATION SYSTEM MAY NOT CALCULATE THE MOST OPTIMAL ROUTE, RANDOMLY AVOID SOME STRETCHES OF HIGHWAY, AND PERFORM UNEXPECTED DETOURS EVEN UNDER GOOD TRAFFIC CONDITIONS. THIS HAPPENS MOSTLY IN AREAS WITH HIGH-OCCUPANCY VEHICLE (HOV) LANES AND EVACUATION ROADS. DEALERS ARE TO INSPECT AND, IF NECESSARY, UPDATE THE NAVIGATION MAP DATABASE WITH AN SD CARD.