2001 BMW X5 4.4i
I'M EXPERIENCING A NON COMMON ISSUE SPECIALLY ON THIS CAR.
AFTER A FULL DIAGNOSTIC, I RECORDED A CODE: (P0412) WHICH IS A SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE A CIRCUIT MALFUNCTION.

I WONDER IF THIS IS EXACTLY THE AIR PUMP OR THE SWITCHING VALVE A CIRCUIT IT MENTIONED. THIS IS A VERY RARE ISSUE WHERE I CAN'T EVEN FIND ANY HELP RELATED ONLINE, BUT UNFORTUNATELY I HAVE TO PASS STATE INSPECTION TO DRIVE THE CAR. WHEN I CLEARED THE CODE FOR THE CHECK ENGINE LIGHT TO TURN OFF, IT DOES GO OUT BUT TURN RIGHT BACK ON, ON THE NEXT START-UP.