The passenger seat occupant sensor is mounted underneath the leather. The seat has to be removed, and the leather removed from the seat. My friend owns a seat upholstery shop and he did it in less then half an hour for $40. The part cost me $130 online. Actually what fails is the wire between the sensor and the harness underneath the seat. The rocket scientists at mercedes strap the wire tightly to a sharp edge underneath the seat and everytime a passenger sits down, it pushes pressure on the wire. Eventually it cuts through and you get the condition you described. There is no way to bypass the sensor because its a totally over engineered data signal device.

The best I can tell it is only useful if your using a Mercedes Infant car seat that plugs into the harness. The passenger airbag off light doesnt come on if there is no passenger like it does on newer american cars. In other words, it's a totally useless, over engineered system that frequently fails and costs Mercedes owners big bucks. A system for an infant car seat THAT SHOULD BE IN THE BACK SEAT ANYWAY. Dealers get about 600 for the repair.

That said, I still love me E320 :-)