Typically only a passenger's seat is equipped with a seat occupancy sensor. There is an exception for some models of BMW - e.g. E65, which has a driver's seat occupancy sensor as well as a back seat occupancy sensor.
Depending on a car model, the seat mat plug can be installed at the front or at the back of the seat. It can be fixed to the car floor or to the seat.
Here you can find the installation instructions with some useful pictures.
Sometimes finding the plug may provide a real challenge. In some models it can be hidden into the seat's foam or under the leather seat upholstery.
ATTENTION! It may turn out that in your car is an atypical kind of a seat mat (with 2 wires) or there is no seat mat at all (because a previous owner removed it).
Car models, in which you should obligatorily check if there is a passenger's seat occupancy sensor and what kind of a plug does it have:
- All Mazda models - in some models the seat mat plug is well hidden and very hard to find.
ATTENTION: in some Mazda models there can be no seat mat or there can be an atypical 2-wired version. - BMW E60/E61 - 2003-2006 models: there is a 2-wired or a 3-wired version (also important whatever it is the US or the European version of a BMW).
- BMW E65/E66 - manufactured 2003-2006: there is a 2-wired or a 3-wired version (also important whatever it is the US or the European version of a BMW).
- BMW E63/E64 - manufactured 2003-2006: there is a 2-wired or a 3-wired version (also important whatever it is the US or the European version of a BMW).
- Mercedes - the US models manufactured 2004-2006. Since about 2005 started installing a different type of a seat mat (WSS with 4 wires).
Learn what else should be checked before buying:
• Professional diagnostics - can I be certain that SRS warning is caused by a faulty seat occupancy sensor?
• What version of a car you own - the EU or the US?
• Will this seat occupancy sensor emulator work on my car?