Rg1620

2009 GL550 w/keyless go. After hitting button to stop engine, normally opening the drivers door will shut the ignition off. In my case it does not. I have to open and close the door multiple times in order for it to sense that the door has been opened. I have tried this even with the key outside the car. The radio remains on and the dash is still lit. How does the drivers door-open sensor work? I don't see a mechanical switch anywhere.

Fourdiesel

There must be a switch or sensor on/in the door somewhere. How else would the 'system' know when to turn stuff off and start other timers, etc.
Ask a dealer where the switch is in the driver's side door.