The table below summarizes the input signals to and output signals from the headlamp control module (HCM). The signal types are divided into directly connected signals, serial communication and CAN communication. The graphic below displays the same information with the Volvo component designations.

Input signals	Output signals
Directly connected:	Directly connected:
Position sensor (7/119, 7/121)	Motor, headlamp levelling (not active headlamps)
Via serial communication:	Via serial communication:
Left headlamp control unit (LHCU)/Right headlamp control unit (RHCU) (vehicles with active headlamps only)	Left headlamp control unit (LHCU)/Right headlamp control unit (RHCU) (vehicles with active headlamps only)
Via Controller Area Network (CAN) communication:	Via Controller Area Network (CAN) communication:
Suspension module (SUM) (4/84) Transmission control module (TCM) (4/28) Brake control module (BCM) (4/16) Engine control module (ECM) (4/46) Steering wheel angle sensor module (SAS) (3/130) Infotainment control module (ICM) (3/281) Central electronic module (CEM) (4/56)	Driver information module (DIM) (5/1) Infotainment control module (ICM) (3/281)

Fig 1: Identifying Input Signals To And Output Signals From Headlamp Control Module (HCM)

Courtesy of VOLVO CARS CORPORATION

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System Overview: Signals

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