BMW E90 Passenger Seat Occupancy Sensor Repair- 2007-2013 3 Series

One of the most annoying issues that owners of 2007-2013 BMWs have to deal with is a passenger-side seatbelt reminder chime and a warning light that remains active when the seat is not occupied. Most owners are reduced to driving around with the seatbelt buckled in an empty passenger seat, or even overriding the system with a seatbelt "blank". Compounding the issue is the fact that replacing the faulty seat occupancy sensor mat (which is causing the issue) is a difficult and extremely expensive procedure. A new BMW E90 seat occupancy sensor mat can cost close to $1000...just for the part itself.

The good news is there is a less expensive solution - installing a seat occupancy sensor emulator and a seatbelt chime bypass device. A seat occupancy sensor emulator is an electronic device that plugs into the passenger seat's wiring harness in place of the defective mat. Its job is to imitate a seat occupancy mat sensor that has been triggered by a passenger - in other words, it sends a signal to the vehicle's control module that the passenger seat is occupied...removing the seatbelt and airbag warning lights on the dashboard. Simply put, it does the same job as buckling the seat belt with no one in the seat. The seatbelt chime bypass device also connects to the wiring harness - it silences the seatbelt warning chime.

Performing a BMW E90 occupancy sensor bypass by installing an emulator is a fairly easy repair, even for the home mechanic. It only takes about 20 minutes and can easily be done in your driveway or garage. The BMW Repair Guide strongly recommends disconnecting the battery after the seat is removed and prior to disconnecting the wiring harnesses - this will prevent causing an inadvertent short which can damage sensitive electronics. We give full step-by-step instructions below, including a video and parts list for your convenience.