Symbol And Ambiance Illumination, Function - GF82.20-P-2100RD

Model 172.4 

Courtesy of MERCEDES-BENZ USA

Shown on model 172.4 as of 01.03.2016 

Courtesy of MERCEDES-BENZ USA

Shown on model 172.4 up to 29.02.2016 

Function requirements, general 

• No overvoltage or undervoltage

Symbol and ambiance illumination in general 

The symbol and ambiance illumination feature provides the illumination of the controls (with adjustable brightness) and the illumination of the vehicle interior.

If the ambient illumination function has been activated via the instrument cluster, it automatically switches itself on when the vehicle is unlocked. This causes "Standing lights actuation active" status to be set, which also activates the switch and controls and symbol illumination and the ambiance illumination.

If the driver door is then opened, the ambient illumination function goes off. The "Standing lights actuation active" status is canceled. The instrument cluster deactivates the switch and controls and symbol illumination.

The controls in the vehicle are illuminated again only after circuit 15R is then switched on.

The symbol and ambiance illumination function consists of the following subfunctions:

• Function sequence for switch and controls and symbol illumination 
• Function sequence for ambiance illumination (with CODE 877 (Ambiance illumination)) 

Additional function requirements, search and symbol illumination 

• Standing lights ON

Function sequence for switch and controls and symbol illumination 

In order to control the search and symbol illumination, the instrument cluster reads in the following signals and evaluates them:

• Status of standing lights actuation, sent by front SAM control unit over the interior CAN
• Instrument illumination brightness control status (continuous adjustment of switch and controls and symbol illumination brightness)

The instrument cluster uses the incoming data to generate the circuit 58d signal and transmits it to the actuation for the search and symbol illumination via the interior CAN to the following control units:

• Radio or COMAND controller unit
• Front SAM control unit
• Automatic air conditioning control and operating unit
• Vario roof control control unit
• Left door control unit
• Right door control unit

The radio or the COMAND controller unit transmits the signal for circuit 58d via the telematics CAN to the following control units:

• Audio/COMAND display
• Audio/COMAND control panel

The front SAM control unit actuates the following components:

• Actuation via the instrument panel LIN:
  • Analog clock (with CODE 246 (Analog clock))
  • Upper control panel control unit
• Actuation via wiper/inside rearview mirror LIN:
  • Overhead control panel control unit
• Direct actuation:
  • Exterior lights switch
  • Electric parking brake switch
  • Ashtray illumination (with CODE 301 (Smoker's package))
  • Armrest stowage compartment illumination (with CODE 876 (Interior lights package))

The overhead control panel control unit directly actuates the switch and controls and symbol illumination of the anti-theft alarm system/emergency call system button group, if the vehicle is equipped with one of the following:

• As of 01.03.2016 with code 882 (Interior monitoring) or code 351 (Emergency call system (HERMES))
• Up to 29.02.2016 with code 882 (Interior monitoring) or code 359 (TELEAID emergency call system) or code 348 (Emergency call/assist system)

Model 172.4

with code 494 (US version)

The switch and controls and symbol illumination for the trunk lid emergency opening switch is actuated by the rear SAM control unit independent of the circuit 58d signal.

The instrument cluster also sends the circuit 58d signal via chassis CAN (up to 29.02.2016) or via chassis CAN 2, front SAM control unit and chassis CAN 1 (as of 01.03.2016) to the following control units:

• CDI control unit or ME-SFI [ME] control unit
• Steering column module control unit

For transmission 722.9:

The CDI control unit or the ME-SFI [ME] control unit transmits the circuit 58d signal via the drive train CAN to the electronic selector lever module control unit.

The electronic selector lever module control unit actuates the switch and controls and symbol illumination of the transmission mode button of the automatic transmission and the shift gate symbol illumination directly.

With transmission 725.0:

The CDI control unit or the ME-SFI [ME] control unit transmits the circuit 58d signal via the drive train CAN to the DIRECT SELECT INTERFACE.

The steering column tube module control unit actuates the following components via steering LIN and the steering wheel electronics:

• Left multifunction steering wheel button group
• Right multifunction steering wheel button group

The automatic air conditioning control and operating unit directly actuates the switch and controls and symbol illumination of the integrated controls.

The Vario roof control control unit actuates the switch and controls and symbol illumination of the Vario roof/power window switch group directly.

The left door control unit actuates the following components:

• Actuation via left door LIN:
  • Driver-side power window and outside mirror adjustment switch group
  • Left seat adjustment switch group (with CODE 275 (Memory package))
• Direct actuation:
  • Left front door central locking interior switch

The right door control unit actuates the following components:

• Actuation via right door LIN:
  • Right seat adjustment switch group (with CODE 275 (Memory package))
• Direct actuation:
  • Right front door central locking interior switch
  • Power window switch group, passenger side

Additional function requirements for ambiance illumination (with CODE 877 (Ambiance illumination)) 

• Circuit 15R ON
• Illumination intensity of ambiance illumination set
• Automatic interior lights switched on via interior lamp automatic function switch
• Circuit 58d supplied by instrument cluster

Function sequence for ambiance illumination (with CODE 877 (Ambiance illumination)) 

Ambiance illumination includes the illumination of the footwells, the center console and the area around the armrest in the doors.

The intensity of the ambiance illumination can be adjusted in five stages using the "Settings", "Light" menu in the instrument cluster.

As of 01.03.2016, three different light colors can also be selected for the ambiance illumination.

In order to control the ambiance illumination, the front SAM control unit reads in and evaluates in the following signals:

• Status of circuit 15, sent by the electronic ignition lock control unit over the interior CAN
• Status of ambiance illumination brightness and light color, sent by the instrument cluster via interior CAN
• Status of the interior lamp automatic function switch read in via wiper/inside rearview mirror LIN

The front SAM control unit sends the request to switch on the ambiance illumination to the following control units via interior CAN:

• Left door control unit
• Right door control unit

The front SAM control unit actuates the following components directly:

• Left front center console ambiance illumination
• Left rear center console ambiance illumination
• Right front center console ambiance illumination
• Right rear center console ambiance illumination

The left door control unit actuates the following components directly:

• Left door handle ambiance illumination
• Front trim piece ambiance illumination, left door
• Rear trim piece ambiance illumination, left door

The right door control unit actuates the following components directly:

• Right door handle ambiance illumination
• Front trim piece ambiance illumination, right door
• Rear trim piece ambiance illumination, right door

In vehicles with code 876 (Interior lights package) or as of 01.03.2016 with code 877 (Ambiance illumination), the following components of the footwell illumination are also actuated while driving (dimmed):

• By the front SAM control unit:
  • Right footwell lamp
  • Left footwell lamp

When unlocking the central locking (CL) the ambiance illumination components are actuated to the configured brightness setting.

Opening a vehicle door or manually switching on the interior illumination causes the ambiance illumination to be actuated at a brightness setting that corresponds to 100 %.

After closing the vehicle door, the ambiance illumination components are actuated again at the previously set brightness setting.

Upon locking the central locking, the function is deactivated following a run-on time of t = 3 s.

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

The status of the respective vehicle door (open/closed) is recorded by the corresponding door lock rotary tumbler switch.

The respective door control unit transmits the status of the door lock rotary tumbler switch via the interior CAN to the front SAM control unit.

The illumination intensity cannot be adjusted in the instrument cluster when the vehicle doors are open. In this case, the ambiance illumination can only be activated or deactivated.

	Search and symbol illumination electrical function schematic	Model 172.4 as of model year 2017	PE82.20-P-2054-97TAB
		Model 172.4 up to model year 2017	PE82.20-P-2054-97TAA
	Electrical function schematic ambiance illumination	Model 172.4 with code 877 (ambient lighting)	PE82.20-P-2053-97TAA
	Overview of interior illumination (IBL) system components		GF82.20-P-9997RD