Exterior light-dependent control of interior lighting, function

P82.20-2028-06

 All CAN signals refer to the passenger compartment CAN bus. The CAN arrows serve only for illustration of the data flow. In each case they refer to the same CAN bus!

Data flow chart

1 CAN signal: "Automatic driving light feature on and off"

2 Brightness signal

3 CAN-signal "Automatic switch-on /switch-off for driving lights"

4 CAN signal "Switch on parking light"

5 CAN signal "Switch-on/off exit lamps"

A1 Instrument cluster

A1r1 Instrument and search illumination rheostat

B32/1 Automatic light switch day-light sensor

Kl. 58d CAN signal "C.58d"

N10/6 Left front SAM control module

N69/1 Left front door control module

N69/2 Right front door control module

N69/3 Left rear door control module

N70s3 Door contact ON and OFF switch

S1 Exterior lamp switch

N69/4 Right rear door control module

N70 Overhead control panel control module

Some of the internal and external lighting features can be controlled depending on the brightness of the outdoor light. For this purpose the "driving light circuit" must be switched to automatic on the instrument cluster (A1).

Three functions can be differentiated for the interior lighting:

 Brightness depending light function for dome lamps

 Brightness depending light function for search illumination (c.58d)

 Light function for entry/exit lamps (always brightness dependent)

Prerequisites:

 Door contact ON and OFF switch (N70s3) in ON position

 (For search illumination and dome lamps only)
"Driving light circuit" set to automatic on instrument cluster (A1). The instrument cluster (A1) then generates the CAN signal "automatic driving light function on" (1).

Brightness dependent light function for dome lamps

 The overhead control panel control module receives the CAN signal "automatic driving light function on" (1) and

 the brightness signal (2) from the automatic light switch daylight sensor (B32/1).

 if the overhead control panel control module interprets the brightness signal (3) as "night", the dome lamps are switched on on request, e.g. when a door is opened, by the overhead control panel control module.

-----------------------------------------------------------------------------------------

Brightness dependent light function for search illumination

 The overhead control panel control module receives the CAN signal "automatic driving light function on" (1) and

 brightness signal (2) from the automatic light switch daylight sensor (B32/1).

 If the overhead control panel control module interprets the brightness signal (3) as "night", it switches the CAN signal "automatic driving light switch-on/switch-off" (3) to ON.

 The left front SAM control module (N10/6) receives the signal and generates the CAN signal "switch on parking lights" (4).

 The instrument cluster (A1) receives the signal and activates the CAN signal c.58d.

 The control modules to which the lights for search illumination are connected, receives the CAN signal c.58d and switches on the lights.

 C.58d is a pulse width-modulated signal, whose on/off ratio can be set between 12 % and 100 % by means of the instrument and search illumination rheostat (A1r1) as soon as the CAN signal "switch on parking lights" (4) is active.
If the automatic light switch daylight sensor (B32/1) is defective the search illumination acts as if "night" were recognized.

-----------------------------------------------------------------------------------------

Light function for entry/exit lamps

 The overhead control panel control module interprets the brightness signal (3) as "night", then it switches on the CAN signal "switch-on/off exit lamps".

 The door control modules (N69/1, N69/2, N69/3, N69/4) receive the signal and actuate the entry/exit lamps accordingly when a door is opened.

 If a malfunction is present, the entry/exit lamps act as if night were recognized and switch on the CAN signal "switch on/off exit lamps". If the voltage is too high/too low, the CAN signal "switch on/off exit lamps" is never switched on.

Change in brightness or door contact ON and OFF switch (N70s3) during brightness dependent light function
If the brightness information for the position of the door contact ON and OFF switch (N70s3) changes, this change is taken into consideration.