Rear Fog Lamp

Fig 1: Identifying Rear Fog Lamp

Courtesy of VOLVO CARS CORPORATION

The rear fog lights (10/46 and 10/53) are activated by pressing the rear fog light button in the light switch module (LSM) (3/111). The central electronic module (CEM) (4/56) receives a request to activate the rear fog light from the light switch module (LSM) via LIN communication. The central electronic module (CEM) powers the lights directly via an output.

The central electronic module (CEM) transmits information via the Controller area network (CAN) to the driver information module (DIM) (5/1) to light the indicator lamp for the rear fog lamps. The central electronic module (CEM) also lights an LED in the button on the light switch module (LSM) which indicates that the rear fog lamps are activated.

The central electronic module (CEM) measures the power consumption on the output which powers the rear fog lamps. In this way information about lamp status can be obtained. In the event of a fault, the central electronic module (CEM) transmits information via the Control area network (CAN) to the driver information module (DIM) which displays a text message.