3: Airbag Sensors on Left-Hand B-Pillar and Right-Hand B-Pillar

R50, R52, R53 -
Airbag Sensors On Left-Hand B-Pillar And Right-Hand B-Pillar

Installation location
The B-pillar airbag sensors are located in the left and right-hand B-pillars.

Left B Pillar:

Key Explanation
1 Airbag sensor, B-pillar left
2 Support

Construction
The left and right-hand B-pillar airbag sensors comprise the following components:
- Lateral acceleration sensor (for detecting a side impact)
- Longitudinal acceleration sensor (for detecting head-on and rear-end collisions)
- Electronic module (for signal processing and data transmission)

The lateral acceleration sensor is at right angles to the vehicle's longitudinal axis.
The longitudinal acceleration sensor is on the vehicle's longitudinal axis.
The left and right-hand B-pillar airbag sensors are identical.

How it works
The acceleration sensors measure both acceleration and deceleration. (deceleration indicates a frontal collision, accelerating indicates a rear-end collision). The side on which the impact occurs is detected by the polarity of the values from the acceleration sensors.
The signals from the acceleration sensors are converted into digital signals in the corresponding electronic module. The electronic module does not analyse this data itself, but sends it to the MRS control unit (messages transferred on a cyclical basis).
The message is analysed in the MRS control unit.