I keep having a engine light coming on in my 550. It is the engine light (not check engine) the orange illuminated motor. It have loosened the gas cap and retightened. The car is running perfectly. The light came on lst week but went back out an hour or so later. There is not message on the system though. What could it be???

 

If the car manual does not tell any options for the malfunction, then, and actually in any case, should have the fault codes read.