System overview: Signals

The chart below summarizes the input signals to and output signals from the headlight control module (HCM). The signal types are divided into LIN communication and CAN communication. The illustration below displays the same information with the Volvo component designations.

Input signals:	Output signals:
Via LIN communication:	Via LIN communication:
Left headlight control unit (LHCU) / right headlight control unit (RHCU)	Left headlight control unit (LHCU) / right headlight control unit (RHCU)
Via CAN communication:	Via CAN communication:
Transmission Control Module (TCM) (4/28) Brake control module (BCM) (4/16) Steering wheel angle sensor module (SAS) (3/254) Climate Control Module (CCM) (3/112). Central electronic module (CEM) (4/56)	Driver information module (DIM) (5/1) Climate Control Module (CCM) (3/112). Central electronic module (CEM) (4/56)

Fig 1: Identifying Headlight Control Module (HCM) Communication System Links

Courtesy of VOLVO CARS OF NORTH AMERICA.