Automatic Headlamp Actuation, Function

Automatic Headlamp Actuation, Function






Function sequence driving through a tunnel
1 Basic prerequisite:
- The daylight provides sufficient visibility.
- It is not raining nor snowing, the windshield wiper is switched off.
- The exterior lamp switch is set to position "Auto"

2 The overhead control panel control module (N70) monitors automatic light switch daylight sensor (B32/1) in addition to the rain sensor and the position of the windshield wiper.

NOTE: Monitoring of the rain sensor and the position of the windshield wiper switch allows the overhead control panel control module to automatically actuate the headlamps in the event of rain or snow.

3 The automatic light switch daylight sensor (B32/1) monitors the intensity of the daylight with the sunlight sensor and the light conditions with the forward-looking light sensor.
4 The vehicle approaches a tunnel:
- The forward-looking light sensor of the automatic light switch daylight sensor (B32/1) recognizes the dark tunnel entrance.
- The automatic light switch daylight sensor (B32/1) actuates the overhead control panel control module (N70) with the "Darkness, light ON" signal.
5 The overhead control panel control module evaluates the signal and transmits the "headlamp ON" signal to the left SAM control module (N10/10) via the passenger compartment CAN bus.
6 The left SAM control module (N10/10), actuated by the instrument cluster via the passenger compartment CAN bus with the "Automatic headlamp switch actuated", relays the "headlamp ON" signal to the right SAM control module (N10/11) rear SAM (N10/8) and actuates simultaneously.
- the parking lamp in the left headlamp unit and
- the low beams or high beams in the right headlamp unit.
7 The right SAM control module (N10/11) and rear SAM control module (N10/8) receive the "headlamp ON" signal.
8 The right SAM control module (N10/11) actuates the
- the parking lamp in the right headlamp unit and
- the low beams or high beams in the left headlamp unit.

NOTE: Actuation of the high beams and low beams depends on the position of the combination switch (S4). If the combination switch (S4) sin the high beams position the high beams in the left and right headlamp unit (E1/E2) is actuated.

9 The rear SAM control module (N10/8) actuates
- the taillamps in the left and right taillamp and
- the left and right license plate lamps (E19/1 and E19/2).
10 The headlamps are switched on automatically, the vehicle then enters the tunnel with its lights on.
11 The automatic light switch daylight sensor (B32/1) remains active in the tunnel and triggers automatic switch-off of the headlamps as soon as it recognizes the light at the tunnel exit.