W251 rear lift gate sensors?

[klaus kallas]

Where are they? 2007 R320. Just purchased this truck, car, van, whatever last week and the tailgate will not pull shut with latch motor. I can slam and it latches but still getting warning on dash and interior lights stay on. Latch is new, installed by Mercedes dealer within last month. Goes up and down fine but will often reopen itself after first cycle. Bummer is dealer is in another state.

Thanks!