LEMON Manuals: Even more car manuals for everyone
Home >> Mercedes Benz >> 2020 >> CLS450 Base >> Repair and Diagnosis >> Accessories & Equipment >> Interior/Illumination Lights >> Electrical System - Body - 257 Chassis 1 Of 8 >> Basic Knowledge >> Automatic Interior Lights Control, Function - GF82.20-P-2200FR

Automatic Interior Lights Control, Function - GF82.20-P-2200FR

Model 257, 290 

up to model year 2021 

G14550256Courtesy of MERCEDES-BENZ USA

Function requirements, general 

Automatic interior lights control in general 

The automatic interior lights control actuates the component parts of the interior illumination (IBL). The appropriate requests are generated automatically. The master control unit for the automatic interior lights control is the front SAM control unit.

The automatic interior lights control function encompasses the following subfunctions:

Additional function requirement for locator lighting 

IMPORTANT The overhead control panel control unit directly reads in the status of the interior lamp automatic function button and sends it to the front SAM control unit over the interior CAN.

Locator lighting 

When unlocking the vehicle via radio, the front SAM control unit activates the locator lighting.

The electronic ignition lock control unit sends the status of the central locking (CL [ZV]) to the front SAM control unit via interior CAN. The front SAM control unit then sends the request to switch on the interior lighting over the interior CAN to the overhead control panel control unit.

The overhead control panel control unit then actuates the following components directly:

The overhead control panel control unit actuates the following components over the roof-LIN:

IMPORTANT If the ambient illumination function is activated through the instrument cluster, it automatically switches itself on through the central locking when the vehicle is unlocked. This leads to the fact that the search and symbol illumination is switched on. The search and symbol lighting function is described in a separate "Symbol and symbol lighting function" document.

The following component parts are also actuated directly for vehicles except code 891 (Premium ambient lighting):

By the front SAM control unit:

By the rear SAM control unit:

For vehicles with code 891 (Premium ambient lighting), the front SAM control unit sends the request to switch-on the ambient lighting over the interior CAN to the ambient lighting control unit. The ambiance illumination control unit then actuates the following components over the vehicle interior ambiance illumination-LIN:

When the central locking is unlocked, all lamps are switched off after expiration of 40 s or immediately if the vehicle is locked again within 3 s after unlocking it.

Additional function requirements for orientation lighting 

Orientation lighting 

When circuit 15C is switched off, the front SAM control unit activates the orientation lighting.

A stationary vehicle is defined via the vehicle speed. The instrument cluster sends the vehicle speed to the front SAM control unit over the user interface CAN (CAN HMI), electronic ignition lock control unit and interior CAN.

The Supplemental Restraint System control unit transmits the status of the driver seat belt buckle via the user interface CAN, the electronic ignition lock control unit and the interior CAN to the front SAM control unit.

The front SAM control unit then sends the request to switch on the interior lighting over the interior CAN to the overhead control panel control unit.

The overhead control panel control unit then actuates the following components directly:

The overhead control panel control unit actuates the following components over the roof-LIN:

The front SAM control unit on vehicles except code 891 (Premium ambient lighting) also actuates the following component parts directly:

For vehicles with code 891 (Premium ambient lighting), the front SAM control unit sends the request to switch-on the ambient lighting over the interior CAN to the ambient lighting control unit. The ambiance illumination control unit then actuates the following components over the vehicle interior ambiance illumination-LIN:

When the vehicle doors are closed, all lights that are switched on are switched off once the OFF delay time has expired. The OFF delay time can be switched on or off using the "Settings" menu in the head unit. The corresponding selection is sent by the head unit via user interface CAN, electronic ignition lock control unit and interior CAN to the front SAM control unit.

Additional function requirements for warning and exit illumination 

IMPORTANT The overhead control panel control unit directly reads in the status of the interior lamp automatic function button and sends it to the front SAM control unit over the interior CAN.

Warning and exit illumination 

When a vehicle door is opened, the front SAM control unit activates the warning and exit illumination.

The front door control unit transmit the status of the front doors (open or closed) to the front SAM control unit via interior CAN.

The rear door control unit transmit the status of the rear doors (open or closed) to the front SAM control unit via interior CAN.

The front SAM control unit evaluates all incoming information and sends the request to switch on the interior lighting to the overhead control panel control unit over the interior CAN.

The overhead control panel control unit actuates the following components directly:

The overhead control panel control unit actuates the following components over the roof-LIN:

For vehicles with code 891 (Premium ambient lighting) the front SAM control unit also sends the request to switch-on the warning and exit illumination over the interior CAN to the following control units:

Depending on which vehicle door has been opened, the following components of the warning and exit illumination are actuated:

The front SAM control unit on vehicles except code 891 (Premium ambient lighting) also actuates the following component parts directly:

For vehicles with 891 (Premium ambient lighting), the front SAM control unit sends the request to switch-on the ambient lighting over the interior CAN to the ambient lighting control unit. The ambiance illumination control unit then actuates the following components over the vehicle interior ambiance illumination-LIN:

On model 257 with code U25 (Door sills with "Mercedes-Benz" lettering, illuminated) or on model 290 with code U25 (AMG illuminated door sills), the front SAM control unit actuates the following entrance illumination components directly:

The illuminated door sill moldings are actuated with different maximum values depending on the ambient brightness. The ambient brightness is detected by the light sensor. The rain/light sensor with additional functions reads in the signals of the light sensor directly, evaluates them and transmits information about the ambient brightness (dimness level) via the rain/light sensor LIN to the front SAM control unit.

IMPORTANT To preserve the on-board electrical system battery (G1), with circuit 15 Off all the activated lamps are switched off after 5 min. when a vehicle door is open and 8 s after the closing of the last vehicle door.

Additional function requirements for load compartment lighting (model 290) or trunk lighting (model 257.3) 

IMPORTANT A stationary vehicle is defined via the vehicle speed. The instrument cluster sends the vehicle speed to the front SAM control unit over the user interface CAN (CAN HMI), electronic ignition lock control unit and interior CAN.

Trunk lighting (model 257.3) or load compartment lighting (model 290) 

When the trunk lid or liftgate is opened, the front SAM control unit activates the trunk lighting or the load compartment lighting.

The rear SAM control unit transmits the status of the trunk lid or the liftgate via interior CAN to the front SAM control unit. The front SAM control unit then sends the request to switch on the trunk lighting or the load compartment lighting over the interior CAN to the rear SAM control unit.

The rear SAM control unit actuates the following components directly:

After closing the trunk lid or the liftgate, all lights that are currently on are switched off.

IMPORTANT To preserve the on-board electrical system battery, all the lights that are switched on are switched off after t = 5 min with the trunk lid open or the liftgate open and circuit 15 OFF.

Interior lighting for ATA alarm (with code 551 (Anti-theft alarm system (ATA))) 

Immediately after triggering an ATA alarm, the front SAM control unit activates the following interior lighting functions:

Additional function requirement for IBL after an accident 

IMPORTANT A stationary vehicle is defined via the vehicle speed. The instrument cluster sends the vehicle speed to the front SAM control unit over the user interface CAN (CAN HMI), electronic ignition lock control unit and interior CAN.

Interior lighting after an accident 

After an accident with airbag deployment, the front SAM control unit activates the interior lighting.

The interior lighting is actuated to provide better orientation for the vehicle occupants and the first aiders following an accident.

If the supplemental restraint system control unit recognizes an accident event, its sends the crash signal to the front SAM control unit over the user interface CAN, electronic ignition lock control unit and interior CAN.

The front SAM control unit additionally recognizes an accident event by evaluating the signals of the integrated crash sensor.

The front SAM control unit evaluates all incoming information and activates the following interior lighting functions:

  Automatic interior lights control electrical function schematic   PE82.20-P-2052-97XBA
  Overview of interior illumination (IBL) system components   GF82.20-P-9997FR