Seat occupancy detection mats are installed in the seat cushion of the driver and passenger seat and if equipped with optional rear airbags, they are also used in the left and right rear seats.

The sensor mat is identical to the mats used in previous models for the MRS systems. The sensor system consists of pressure sensors that use an electronic evaluation unit (SBE) to detect whether there is weight on the seat.

Fig 1: Identifying Seat Occupancy Detection Mats (1 Of 2)

Courtesy of BMW OF NORTH AMERICA, INC.

As of a weight of approx. 12 kg (26.4lbs.), the seat is recognized as occupied. The electronic evaluation units of the seat occupation mats are connected to the relevant satellites. (SSFA/SSBF=sensors for front seat, SSH=sensors for rear seat)

The information regarding seat occupation is required for activation of the following functions:

Airbag activation
Activation of the seatbelt tensioners and/or end fitting tensioners
Triggering the active head restraints
Automatic positioning of the rear head-restraints

Fig 2: Identifying Seat Occupancy Detection Mats (2 Of 2)

Courtesy of BMW OF NORTH AMERICA, INC.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Seat Occupancy Detection

Use the Manual With the Right Hardware

When to See a Mechanic

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