Switch, Controls And Symbol Illumination, Function - GF82.20-P-2102FR

Model 257, 290 

up to model year 2021 

Courtesy of MERCEDES-BENZ USA

Function requirements, general 

• No overvoltage or undervoltage

Search and symbol illumination 

The switch and controls and symbol illumination implements the brightness-adjustable illumination of all controls.

Activating the switch and controls and symbol illumination makes it easier for the vehicle occupants to find important controls and to look for objects in the vehicle without having to switch on the ignition or the exterior lights to do so.

The search and symbol illumination is switched on by unlocking the vehicle remotely, by opening a vehicle door or by changing the status of circuit 15. The luminosity to be used to implement the search and symbol illumination can be continuously adjusted using the instrument illumination brightness control on the exterior lights switch. The front SAM control unit reads in the signals from the instrument illumination brightness control directly and sends them via interior CAN, electronic ignition lock control unit and user interface CAN to the instrument cluster.

After unlocking the vehicle or opening a vehicle door, the switch and controls and symbol illumination is switched on with 100 % luminosity.

The electronic ignition lock control unit sends the status of the central locking system and the status of circuit 15 over the user interface CAN to the instrument cluster.

The front door control units send the status of the front doors (open or closed) via interior CAN, electronic ignition lock control unit and user interface CAN to the instrument cluster.

The rear door control units send the status of the rear doors (open or closed) via interior CAN, electronic ignition lock control unit and user interface CAN to the instrument cluster.

The instrument cluster evaluates all incoming information, generates the circuit 58d signal and transmits it via the user interface CAN to the following control units to activate the search and symbol illumination:

• Electronic ignition switch control unit
• Head unit

The electronic ignition lock control unit actuates the following component:

• KEYLESS GO start/stop button

The head unit activates the integrated controls and sends the circuit 58d signal over the telematics CAN to the following control units, which then switch on the integrated controls:

• Audio/COMAND display
• Audio/COMAND control panel (except code 446 (Touchpad only))
• Touchpad (with code 446 (Touchpad only) or model 257 with code 448 (Touchpad))

The Audio/COMAND control panel (except code 446 (Touchpad only)) or the touchpad (with code 446 (Touchpad only) or model 257 with code 448 (Touchpad)) transmits the circuit 58d signal via the LCP-LIN to the following control panels, which then actuate the integrated control elements:

• Upper control panel control unit
• Left lower control panel
• Right lower control panel

The electronic ignition lock control unit sends the circuit 58d signal via the chassis FlexRay to the steering column tube module control unit.

The steering column tube module control unit actuates the following components:

• Actuation over steering wheel CAN and steering wheel electronics:
  • Instrument cluster multifunction steering wheel button group
  • Head unit multifunction steering wheel button group
• Direct actuation:
  • DIRECT SELECT lever

The electronic ignition lock control unit sends the circuit 58d signal via interior CAN to the following control units:

• Front SAM control unit
• Rear SAM control unit
• Climate control control unit
• Left front door control unit
• Right front door control unit
• Left rear door control unit
• Right rear door control unit
• Overhead control panel control unit

The front SAM control unit actuates the following components:

• Actuation via the instrument panel LIN:
  • Analog clock
  • Driver's side instrument panel button group (model 257 with engine 256 and code 540 (Electric roller sunblind for rear window), code 235 (Parking Pilot with PARKTRONIC), code 23P (Driving Assistance Package), code 243 (Active Lane Keeping Assist), code 463 (Head-up display), code P20 (Driving Assistance Plus Package), code 489 (AIR BODY CONTROL))
• Direct actuation:
  • Exterior lights switch
  • Cigarette lighter with front ashtray illumination (with code 301 (Ashtray package/smoker package))
  • Center console armrest stowage compartment switch and controls illumination
  • Front center console cup holder illumination (except code 891 (Premium ambient lighting))
  • Right front footwell lamp
  • Left front footwell lamp
  • Electric parking brake switch

The rear SAM control unit actuates the following components directly:

• Left rear footwell lamp
• Right rear footwell lamp

The climate control control unit actuates the search and symbol illumination of the following components via A/C operating LIN:

• Climate control operating unit
• Rear air conditioning operating unit (with code 581 (Automatic air conditioning))

The left front door control unit actuates the following components:

• Actuation via left front door LIN:
  • Driver-side power window and outside mirror adjustment switch group
  • Left front seat adjustment switch group (with code 278 (Fully electric front seats) or code 275 (Memory Package))
  • Left front seat climate control switch group (with code 401 (Seat climate control for driver and front passenger) or code 873 (Seat heating for driver and front passenger) or code 902 (Seat heating Plus for driver and front passenger))
• Direct actuation:
  • Trunk lid release button (model 257 except code 881 (Remote trunk closing))
  • Driver trunk lid/liftgate control button (model 257 with code 881 (Remote trunk closing), model 290)
  • Left front door central locking interior switch
  • Driver's door fully electric trailer hitch switch (with Code 550 (Trailer hitch))

The right front door control unit actuates the following components:

• Actuation via right front door LIN:
  • Right front seat adjustment switch group (with code 278 (Fully electric front seats) or code 275 (Memory Package))
  • Right front seat climate control switch group (with code 401 (Seat climate control for driver and front passenger) or code 873 (Seat heating for driver and front passenger) or code 902 (Seat heating Plus for driver and front passenger))
• Direct actuation:
  • Passenger-side power window switch
  • Right front door central locking interior switch

The left rear door control unit actuates the following components:

• Actuation via left rear door LIN:
  • Left rear seat seat climate control switch group (with code 872 (Seat heater in rear))
• Direct actuation:
  • Left rear power window switch

The right rear door control unit actuates the following components:

• Actuation via right rear door LIN:
  • Right rear seat seat climate control switch group (with code 872 (Seat heater in rear))
• Direct actuation:
  • Right rear power window switch

The overhead control panel control unit actuates the following component part via the roof LIN:

• Surround lamp in inside mirror

Eyeglass box illumination 

The overhead control panel control unit directly actuates the eyeglasses box illumination irrespective of the circuit 58d signal from a circuit 15R ON status onwards.

Trunk lid/liftgate control button (model 257 with code 881 (Remote trunk closing), model 290): 

The rear SAM control unit actuates the trunk lid/liftgate control button with an opened trunk lid (model 257) or opened liftgate (model 290) directly irrespective of circuit 58d signal. The rear SAM control unit independently evaluates the status of the trunk lid or the liftgate (open or closed).

Trunk lid emergency opening function switch (model 257 with code 460 (Canada version) or code 494 (USA version)): 

The rear SAM control unit actuates the trunk lid emergency opening switch directly irrespective of the circuit 58d signal. After the trunk lid is closed, the trunk lid emergency opening switch is actuated for 60 min with a frequency of 1 Hz and flashes green. The rear SAM control unit independently evaluates the status of the trunk lid (open or closed).

	Search and symbol illumination electrical function schematic		PE82.20-P-2054-97XBA
	Overview of interior illumination (IBL) system components		GF82.20-P-9997FR