check engine light on 1991 Mercedes-Benz 300E

When I get into the car without even putting the key in the ignition, the check engine light is on. After I start the car, the check engine light goes off. What is the cause of this?

Asked by for the 1991 Mercedes-Benz 300E
you have a problem either in the instrument cluster or in the wiring. either way, you will need a good local MB
shop to diagnose this for you.