Ultrasonic Sensor Module (IMS) (XC90 My 2012-).

Fig 1: Identifying Ultrasonic Sensor Module (IMS)

Courtesy of VOLVO CARS CORPORATION

The ultrasonic sensor module (IMS) is located in a cover on the ceiling. The ultrasound sensor (IMS) is used to detect movement inside the passenger compartment when the alarm is activated. The aim is to detect, for example, anybody attempting to reach into the vehicle to steal a bag or similar. When the sensor is activated it performs an internal self-test and reports the result to the CEM, if the test failed the CEM sets a DTC. The sensors communicate serially and are powered via the Upper electronic module (UEM). When the sensor is activated, it emits ultrasound in the passenger compartment. The sound waves are reflected back to the sensor and if the sensor detects changes in reflectivity or movements inside the passenger compartment, the alarm is triggered.