Headlight switch off delay function

Function requirements for headlamp switch-off delay (SWA), general

 Function activated via instrument cluster (A1)

 Engine switched off and transmitter key (A8/1) removed

 Light activation sensor (B32/1)
(without code (345) Rain sensor) or
rain/light sensor (B38/2) (with code (345) Rain sensor)
signals darkness

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SWA, general

The SWA is used for leaving and finding the vehicle safely in darkness by switching on the vehicle ambient illumination.

SWA comprises the following subfunctions:

 Function sequence for SWA

 Function sequence for locator lighting (AFB)

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Function sequence for SWA

The following information is evaluated by the front SAM control unit with fuse and relay module (N10/1) for output of the headlamp switch-off delay function:

- Activated SWA function by the instrument cluster

- Circuit status of circuit 15 from the EIS [EZS] control unit (N73)

- Status of light activation sensor or
status of rain/light sensor from overhead control panel control unit (N70)

Once the engine is switched off and the transmitter key is removed from the electronic ignition switch control unit the vehicle ambient illumination is switched on for a period of t =
60 s. When a door or the trunk lid is opened, the function sequence starts again.

The status of the doors and the trunk lid is made available by the rear SAM control unit with fuse and relay module (N10/2) via the interior CAN.

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The front SAM control unit evaluates all of the relevant information and transmits an appropriate signal via the interior CAN to the rear SAM control unit.

The following components of the vehicle ambient illumination are actuated by the front SAM control unit:

- Left standing light / parking light (E1e3)

- Left front standing light 2 (E1e12)

- Right standing light / parking light (E2e3)

- Right front standing light 2 (E2e12)

- Left front fog lamp (E5/1)

- Right front fog lamp (E5/2)

The following components of the vehicle's ambient illumination are actuated by the rear SAM control unit:

- Upper left taillight and parking light (E3e6)

- Lower left taillight and brake light (E3e7)

- Upper right taillight and parking light (E4e6)

- Lower right taillight and brake light (E4e7)

- Left license plate lamp (E19/1)

- Right license plate lamp (E19/2)

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 By briefly switching on circuit 15 after switching off the engine it is possible to discretely leave the vehicle without activating the SWA.

The active headlamp switch-off delay is terminated immediately by switching on circuit 15 or by triggering an anti-theft alarm system (ATA [EDW]) alarm (with code (551) Anti-theft alarm system (ATA [EDW])).

Function sequence for AFB

The vehicle ambient illumination is switched on for a period of
t = 40 s when the vehicle is unlocked by means of the transmitter key. The request "Unlock vehicle" is transmitted to the front SAM control unit by the electronic ignition switch control unit via the interior CAN.

The front SAM control unit actuates the components of the vehicle's ambient illumination in the front area and transmits the switch-on request to the rear SAM control unit via the interior CAN. The components are actuated as described for the SWA function. The AFB function is terminated by opening a vehicle door, by inserting the transmitter key into the EIS [EZS] control unit or by triggering an ATA [EDW] alarm.

 The headlamp switch-off delay and locator lighting functions run in parallel if necessary. An active SWA function is not terminated by a requested AFB function and vice versa.