Headlight Switch Off Delay Function - GF82.10-P-2011RDM

Model 172.4 as of model year 2017 

Function requirements, general 

• No overvoltage or undervoltage (operating voltage range U ≥ 7 ≤ 17.5 V)
• "Ambient illumination" function activated in "Settings", "Light" menu in instrument cluster (A1)
• Light sensor (B38/1) (except code 345 (Windshield wiper with rain sensor)) or rain/light sensor (B38/2) (with code 345 (Windshield wiper with rain sensor)) signals "Darkness detected"
• Exterior lights switch (S1) in position "A"

The instrument cluster sends the status of the "ambient illumination" function over the interior CAN (CAN B) to the front SAM control unit with fuse and relay module (N10/1).

The front SAM control unit reads in the status of the rain/light sensor via wiper/inside rearview mirror LIN (LIN 2).

The front SAM control unit reads in the status of the exterior lights switch directly.

Headlamp switch-off delay (SWA), general 

The SWA function is used for leaving and finding the vehicle safely in darkness.

The following light functions are activated here:

• Standing/parking lights actuation
• Ambient illumination over left outside mirror ambient lamp (M21/1e1) in the left outside mirror (M21/1) and right outside mirror ambient lamp (M21/2e1) in the right outside mirror (M21/2) (with code 876 (Interior lights package))

Model 172.4 as of model year 2017 with code 876 (Interior Light package)

The outside mirror ambient lamps are only actuated when the outside mirrors are completely folded out. As from 01.12.2016, the photographic image projected onto the ground will appear in 3D look.

Detailed information about the standing/parking lights actuation is available in a separate document.

The SWA function is comprised of the following subfunctions:

• Function sequence for headlamp switch-off delay (SWA) 
• Function sequence for locator lighting (AFB) 

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

Function sequence for headlamp switch-off delay (SWA) 

The headlamp switch-off delay function is activated after the driver switches off the engine (change in status of circuit 15 On to circuit 15R On) for t = 60 s. The electronic ignition lock control unit (N73) sends the status of circuit 15 to the front SAM control unit via interior CAN.

The front SAM control unit then activates the standing/parking lights actuation. In vehicles with code 876 (Interior lights package), the front SAM control unit sends the request to switch on the ambient illumination over the interior CAN to the following control units:

• Left door control unit (N69/1)
• Right door control unit (N69/2)

The left door control unit actuates the left outside mirror ambient lamp. The right door control unit actuates the right outside mirror ambient lamp.

The function starts again by opening a door. The trunk lid is evaluated here as a vehicle door. If all vehicle doors are then closed again, the function starts again.

The status of the respective door is sent by the left door control unit or the right door control unit, the status of the trunk lid is sent by the rear SAM control unit with fuse and relay module (N10/2) via interior CAN to the front SAM control unit.

The active SWA is interrupted by switching on circuit 15 or by triggering an ATA [EDW] alarm (with code 551 (Anti-theft alarm system (ATA [EDW]))). The rear SAM control unit sends the status of the ATA [EDW] via interior CAN to the front SAM control unit.

Function sequence for locator lighting (AFB) 

When unlocking the vehicle using a radio frequency or infrared, the ambient illumination is switched on for a period of t = 40 s (time for the automatic relocking).

The electronic ignition lock control unit sends the status of the central locking via interior CAN to the front SAM control unit.

The front SAM control unit then activates the standing/parking lights actuation.

At the same time, the front SAM control unit in vehicles with code 876 (Interior lights package) sends the request to switch on the ambient illumination over the interior CAN to the door control units. The left door control unit actuates the left outside mirror ambient lamp. The right door control unit actuates the right outside mirror ambient lamp.

In vehicles with code 640 (High Performance LED) or code 641 (Dynamic left-hand traffic LED headlamp) or code 642 (Dynamic right-hand traffic LED headlamp), the front SAM control unit sends the request to switch on the ambient illumination over chassis CAN 2 (CAN E2) to the following control units:

• Left headlamp control unit (E1n9)
• Right headlamp control unit (E2n9)

The left headlamp control unit actuates the left front ambient light (E1e23) and the left front position light (E1e31) in the left front lamp unit (E1) accordingly. The right headlamp control unit actuates the right front ambient light (E2e23) and the right front position light (E2e31) in the right front lamp unit (E2) accordingly.

The ambient lights in the front lamp units light up for a period of t = 2 s in blue and then turn white after a transition phase.

If an engine start is detected within t = 40 s, a change is made from the locator lighting to the on/off driving lights function. Detailed information on the auto on/off driving lights is available in a separate document.

	Electrical function schematic, headlamp switch-off delay (SWA)		PE82.10-P-2062-97TAB
	Overview of exterior lights system components		GF82.10-P-9998RDM