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Home >> Volvo >> 2011 >> S40 T-5 R-Design >> Repair and Diagnosis >> Electrical >> Charging Systems >> Electrical Components - Design And Function (544 Body) >> Central Electronic Module (CEM) (2004-2011) >> Design >> Back-Up Lamp
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Back-Up Lamp

Fig 1: Identifying Rear Fog Lamps
GLL128552Courtesy of VOLVO CARS OF NORTH AMERICA.

There are two back-up (reversing) lamps. These are in the tail lamps. The back-up (reversing) lamp lights when back-up (reverse) gear is selected. The back-up (reversing) lamps are connected to the central electronic module (CEM) via a directly connected relay. The lamps are powered via the relay.

Cars with manual transmissions 

Cars with manual transmissions have a back-up (reverse) switch on the transmission. The switch closes and transmits a directly connected signal to the central electronic module (CEM) when back-up (reverse) gear is selected.

Cars with automatic transmissions 

In cars with automatic transmissions, a signal is transmitted from the transmission control module (TCM) on the controller area network (CAN) to the central electronic module (CEM) indicating that back-up (reverse) gear is selected.

There are diagnostics for the back-up (reversing) lamp relay.