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

Model 172.4 up to model year 2017 

Function requirements, general 

• No overvoltage or undervoltage (operating voltage range U ≥ 7 ≤ 17.5 V)
• "Ambient illumination:" function activated in "Settings" menu under "Light" in the instrument cluster (A1)
• Light sensor (B38/1) (without code 345 (Windshield wiper with rain sensor)) or rain/light sensor (B38/2) (with code 345 (Windshield wiper with rain sensor)) signals "Darkness recognized"
• Exterior lights switch (S1) in position "A"

Headlamp switch-off delay (SWA), general 

The SWA function is used for leaving and finding the vehicle safely in darkness by switching on the vehicle's exterior lights (ambient illumination).

The SWA function is comprised of the following subfunctions:

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

Function sequence for headlamp switch-off delay (SWA) 

After the driver switches off the engine (change in status of circuit 15 ON to circuit 15R ON) the SWA function is then requested.

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, transmitted by the instrument cluster via the interior CAN (CAN B)
• Status of circuit 15, transmitted by the electronic ignition lock control unit (N73) via the interior CAN
• Status of light sensor or rain/light sensor, read in via the wiper/inside rearview mirror LIN (LIN 2)
• Status of exterior lights switch, read in directly

After switching off the engine, the ambient illumination is switched on for a fixed time interval of t = 60 s. The time interval starts again by opening a vehicle door. The trunk lid is assessed as a vehicle door. If all vehicle doors are closed again, the function is restarted.

The status of the doors is transmitted by the left door control unit (N69/1) and the right door control unit (N69/2), and the status of the trunk lid is transmitted by the rear SAM control unit with fuse and relay module (N10/2) via the interior CAN to the front SAM control unit.

The front SAM control unit evaluates all of the relevant information and transmits the request to switch on the ambient illumination via interior CAN to the following control units:

• Rear SAM control unit
• Left door control unit (with code 876 (Interior lights package))
• Right door control unit (with code 876 (Interior lights package))

The front SAM control unit actuates the following components:

• Left front lamp unit (E1)
• Left front standing light and parking light (E1e3)
• Left front side marker light (E1e6)
• Right front lamp unit (E2)
• Right front standing light and parking light (E2e3)
• Right front side marker lamp (E2e6)
• Also in vehicles with code 615 (Bi-xenon headlamps with active curve lights) or code 621 (Intelligent Light System (left-hand traffic)) or code 622 (Intelligent Light System):
  • Left xenon light power supply module (E1n4) and thus the left xenon bulb with integrated ignition module (E1e10)
  • Right xenon light power supply module (E2n4) and thus the right xenon bulb with integrated ignition module (E2e10)
• Also in vehicles without code 240 (LED daytime running lamps) and without code 615 (Bi-xenon headlamps with active curve lights) and without code 621 (Intelligent Light System (left-hand traffic)) and without code 622 (Intelligent Light System):
  • Left front fog lamp (E5/1)
  • Right front fog lamp (E5/2)

The rear SAM control unit actuates the following components:

• Left rear lamp unit (E3)
• Inner left brake light and taillight (E3e10)
• Outer left brake light and taillight (E3e11)
• Right rear lamp unit (E4)
• Inner right brake light and taillight (E4e10)
• Outer right brake light and taillight (E4e11)
• Left license plate lamp (E19/1)
• Right license plate lamp (E19/2)
• Also in vehicles with code 460 (Canada version) or code 494 (USA version):
  • Left rear side-marker light (E3e6)
  • Right rear right rear side-marker light (E4e6)

The left door control unit actuates the left outside mirror ambient lamp (M21/1e1) (with code 876 (Interior lights package)) in the left outside mirror (M21/1).

The right door control unit actuates the right outside mirror ambient lamp (M21/2e1) (with code 876 (Interior lights package)) in the right outside mirror (M21/2).

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

Function sequence for AFB 

When unlocking the vehicle using radio frequency or infrared, the ambient illumination is switched on for a period of t = 40 s (time for 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 evaluates this and transmits the "ambient illumination ON" request via the interior CAN to the rear SAM control unit and in vehicles with code 876 (Interior lights package) to the door control units.

The components of the exterior lights are actuated as described for the headlamp switch-off delay function.

The locator lighting function is terminated by opening a door, when circuit 15C is switched on or when an ATA [EDW] alarm is triggered.

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.

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