Front Impact Sensor (Not XC60)
The front impact sensors are used to provide the supplemental restraint system module (SRS) with advance information about the collision pulse. This enables the control module to more accurately determine which components to deploy.
The front impact sensors have integrated logic which transmits acceleration data to the supplemental restraint system module (SRS).
In the event of a collision, the control module calculates the acceleration data from the front impact sensors and the internal sensors of the control module to determine if the impact is sufficiently severe to deploy the impact protection.
The control module generates one or more diagnostic trouble codes if one or both of the front impact sensor fail. A diagnostic trouble code is also generated if communication between the control module and either of the front impact sensors fails.
If one (or both) of the front impact sensors stops working for some reason, the control module uses the internal acceleration sensor 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 front impact sensor and a ground cable.
The front impact sensors are located behind the left and right headlights, respectively.
Each front impact sensor has a specific ID that is used to check that the right front impact sensor is installed in the vehicle.
Vehicles with Closing velocity module (CVM) (only XC60) have no frontal impact sensor. These vehicles use information from the internal acceleration sensor in the Supplemental Restraint System Module (SRS) as well as information from Closing velocity module (CVM) to give Supplemental Restraint System Module (SRS) early information in case of a frontal collision.