My car gets the gas cap open red indicator and flashing gas pump now check eng o

It's has been my technical experience that some of today's Mercedes Benz & Smart vehicles may demonstrate your similar if not exact symptoms of flashing indicators when there is a malfunction within the fuel evaporative emission system. I would highly recommend taking your vehicle into your local Top shop or equivalent for precise troubleshooting into your vehicle present malfunction. If you happen to commute into Chicago NorthSide area we would be happy to inspect your vehicle. If not best of wishes and we all look forward to what resolves your vehicle low fuel indicator(s) Michael Moran Jr Shop Foreman

The gas cap light is on because there is a fault in the EVAP system. Next step is to bring it in and have a smoke test performed to ring the cause of the leak in the system. In short the light is on because the system isn't sealed