Blower Fan

Fig 1: Identifying Central Electronic Module (CEM)

Courtesy of VOLVO CARS OF NORTH AMERICA.

The blower fan is brushless, of the permanent magnet type. It supplies airflow through the vehicle, and must be running for the climate control to connect.

The blower fan is controlled via a PWM signal from the Central electronic module (CEM). The Climate control module (CCM) controls the speed of the blower fan with a request to the Central electronic module (CEM) via the CAN network.

The blower fan can be diagnosed via the Central electronic module (CEM), among others, via a PWM control signal that it sends back to the Central electronic module (CEM).