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Side Impact Sensor

Fig 1: Identifying Side Impact Sensors
GLL160839Courtesy of VOLVO CARS CORPORATION

The vehicle's side impact sensors are used to provide the supplemental restraint system (SRS) early information on a side-on collision.

The four sensors used in the car are: 

The side impact sensors in the B and C posts consist of acceleration sensors that continuously send data to the control module.

The side impact sensors (pressure sensors) in the doors consist of air pressure sensors that continuously transmit data to the control module.

In case of a collision Supplemental Restraint System Module (SRS) uses data from the sensors and from an acceleration sensor, installed internally in the control module, to decide if the collision force is sufficient to active the side impact protection.

Only the side impact protection system nearest the point of impact is deployed.

The control module generates one or more diagnostic trouble codes if one or both of the side impact sensor fail. A diagnostic trouble code is also generated if communication between the control module and either of the side impact sensors fails.

If one (or both) of the side impact sensors stops working for some reason, the control module uses information from the other sensors to determine when to deploy the impact protection.

Data is transmitted on the same cable used for power supply. There is a signal/power supply cable to each side impact sensor and a ground cable.

The four side impact sensors in the B and C posts are of the same type, therefore, they can be installed in all four positions.

The side impact sensors (pressure sensors) in the doors are of the same type and can be installed in either the left or right-hand doors.

Each front impact sensor has a specific ID that is used to check that the right front impact sensor is installed in the vehicle.