Assuming you are referring to the Orange one on the left, the handbook says " If the car drives normally, arrange a service appointment. If light flashes and/or car does not drive normally, avoid high speeds and seek immediate assistance." Mine used to come on when i got the car, and i found that it happened more often if i had been idling the engine for any length of time whilst tinkering with things. when it did come on, it would stay on for the next two or three trips, and then reset. So from my experience if the car is driving normally i don't worry, and it goes out after a couple of days. i suspect it is a rich mixture thing.