Back-up lamp

Fig 1: Identifying Back-Up Lamp Communication Links And Components

Courtesy of VOLVO CARS OF NORTH AMERICA.

Manual transmissions 

The back-up (reversing) lamps (10/48, 10/55) are activated when back-up (reverse) gear is selected. The switch (3/10) on the transmission is then closed. A directly connected signal is transmitted to the central electronic module (CEM) (4/56) indicating that back-up (reverse) gear is selected. The central electronic module (CEM) transmits the information via the controller area network (CAN) to the rear electronic module (REM) (4/58) to activate the back-up lamps. The rear electronic module (REM) activates the relay and the back-up lamps are supplied with power via the relay.

Automatic transmission 

The back-up (reversing) lamps (10/48, 10/55) are activated when back-up (reverse) gear is selected. The transmission control module (TCM) (4/28) transmits information via the Control area network (CAN) to the central electronic module (CEM) (4/56) indicating that back-up (reverse) gear is selected. The central electronic module (CEM) transmits the information via the controller area network (CAN) to the rear electronic module (REM) (4/58) to activate the back-up lamps. The rear electronic module (REM) activates the relay and the back-up lamps are supplied with power via the relay.