Automatic Interior Lights Control, Function - GF82.20-P-2200FH
Model 238
Up To Model Year 2021
Function requirements, general
- No overvoltage or undervoltage
Automatic interior lights control in general
The automatic interior lights control actuates all the components 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:
- Locator lighting function sequence
- Function sequence for orientation lighting
- Function sequence for warning and exit illumination
- Function sequence for trunk illumination
- Function sequence for interior illumination for ATA [EDW] alarm (with CODE 551 (Anti-theft alarm system (ATA [EDW])))
- Function sequence for interior illumination after an accident
Additional function requirement for locator lighting
- Automatic interior lights switched on using the interior lamp automatic function button
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 function sequence
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. Then the front SAM control unit transmits the request to switch on the interior illumination via the interior CAN to the overhead control panel control unit.
The overhead control panel control unit then actuates the following components directly:
- Front dome lamp (model 238.3)
- Left interior/reading lamp (model 238.4)
- Right interior/reading lamp (model 238.4)
- Rear interior lamp in rear passenger compartment dome lamp (for model 238.3 standard equipment, for model 238.4 with code 877 (Ambient lighting) or code 891 (Premium ambient lighting))
The overhead control panel control unit actuates the following components over the roof-LIN:
- Left reading lamp in inside rear-view mirror
- Right reading lamp in inside rear-view mirror
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 symbol and ambiance illumination function is described in a separate document.
Additionally, the front SAM control unit actuates the following component parts directly in vehicles without code 877 (Ambient lighting) and without code 891 (Premium ambient lighting):
- Right front footwell lamp
- Left front footwell lamp
In vehicles with code 877 (Ambient lighting) or code 891 (Premium ambient lighting), the front SAM control unit transmits the request to the ambient lighting control unit via the interior CAN. The ambiance illumination control unit then actuates the following components over the vehicle interior ambiance illumination-LIN:
- Right front footwell lamp
- Left front footwell lamp
- Right rear footwell lamp
- Left rear footwell lamp
When the central locking is unlocked, all lamps are switched off after expiration of t = 40 s or immediately if the vehicle is locked again within t = 3 s after unlocking it.
Additional function requirement for orientation lighting
- Vehicle standing still (v = 0 km/h)
- Driver seat belt buckle opened
Function sequence for orientation lighting
When circuit 15C is switched off, the front SAM control unit activates the orientation lighting.
The instrument cluster sends the vehicle speed via user interface CAN to the electronic ignition lock control unit. The electronic ignition lock control unit sends the vehicle speed and the status of the driver seat belt buckle over the interior CAN to the front SAM control unit. Then the front SAM control unit transmits the request to switch on the interior illumination via the interior CAN to the overhead control panel control unit.
The overhead control panel control unit then actuates the following components directly:
- Front dome lamp (model 238.3)
- Left interior/reading lamp (model 238.4)
- Right interior/reading lamp (model 238.4)
- Rear interior lamp (for model 238.3 standard equipment, for model 238.4 with code 877 (Ambient lighting) or code 891 (Premium ambient lighting))
The overhead control panel control unit actuates the following components over the roof-LIN:
- Left reading lamp in inside rear-view mirror
- Right reading lamp in inside rear-view mirror
Additionally, the front SAM control unit actuates the following component parts directly in vehicles without code 877 (Ambient lighting) and without code 891 (Premium ambient lighting):
- Right front footwell lamp
- Left front footwell lamp
In vehicles with code 877 (Ambient lighting) or code 891 (Premium ambient lighting), the front SAM control unit transmits the request to the ambient lighting control unit via the interior CAN. The ambiance illumination control unit then actuates the following components over the vehicle interior ambiance illumination-LIN:
- Right front footwell lamp
- Left front footwell lamp
- Right rear footwell lamp
- Left rear footwell lamp
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
- Automatic interior lights switched on using the interior lamp automatic function button
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.
Function sequence for 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 front SAM control unit evaluates all incoming information and sends the request to switch on the interior illumination to the overhead control panel control unit over the interior CAN.
The overhead control panel control unit then actuates the following components directly:
- Front dome lamp (model 238.3)
- Left interior/reading lamp (model 238.4)
- Right interior/reading lamp (model 238.4)
- Rear interior lamp (for model 238.3 standard equipment, for model 238.4 with code 877 (Ambient lighting) or code 891 (Premium ambient lighting))
The overhead control panel control unit actuates the following components over the roof-LIN:
- Left reading lamp in inside rear-view mirror
- Right reading lamp in inside rear-view mirror
The front SAM control unit also sends the request to switch on the warning and exit illumination to the following control units over the interior CAN:
- Left front door control unit
- Right front door control unit
In vehicles with code 877 (Ambient lighting) or code 891 (Premium ambient lighting), the following components parts of the warning and exit illumination are actuated depending on which of the vehicle doors has been opened:
- Left door exit lamp and left door warning lamp by the left front door control unit
- Right door exit lamp and right door warning lamp by the right front door control unit
Additionally, the front SAM control unit actuates the following component parts directly in vehicles without code 877 (Ambient lighting) and without code 891 (Premium ambient lighting):
- Right front footwell lamp
- Left front footwell lamp
In vehicles with code 877 (Ambient lighting) or code 891 (Premium ambient lighting), the front SAM control unit transmits the request to the ambient lighting control unit via the interior CAN. The ambiance illumination control unit then actuates the following components over the vehicle interior ambiance illumination-LIN:
- Right front footwell lamp
- Left front footwell lamp
- Right rear footwell lamp
- Left rear footwell lamp
In vehicles with code U25 (Door sills with "Mercedes-Benz" lettering, illuminated), the front SAM control unit actuates the following entrance illumination components directly:
- Left front illuminated door sill molding
- Right front illuminated door sill molding
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.
To preserve the on-board electrical system battery (G1), with circuit 15 Off all the activated lamps are switched off after t = 5 min. when a vehicle door is open and t = 8 s after the closing of the last vehicle door.
Additional function requirement for trunk illumination
- Vehicle stationary
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.
Function sequence for trunk illumination
When the trunk lid is opened, the front SAM control unit activates the trunk illumination.
The rear SAM control unit sends the status of the trunk lid to the front SAM control unit via interior CAN. The front SAM control unit then sends the request to switch on the ambient illumination over the interior CAN to the rear SAM control unit.
The rear SAM control unit actuates the following components directly:
- Trunk lamp (model 238.3)
- Right trunk lamp (model 238.4)
- Left trunk lamp (model 238.4)
- Left trunk lid/liftgate load compartment lamp and warning lamp (model 238.4)
- Trunk lid load compartment lamp (model 238.3)
- Trunk lid warning lamp (model 238.3)
After closing the trunk lid, all switched-on lights are switched off.
To preserve the on-board electrical system battery, all the lights that are switched on when the trunk lid is open and with circuit 15 OFF are switched off after t = 5 min.
Function sequence for interior illumination for ATA [EDW] alarm (with CODE 551 (Anti-theft alarm system (ATA [EDW])))
Immediately after triggering an ATA [EDW] alarm, the front SAM control unit activates the following interior illumination functions:
- Locator lighting
- Search and symbol illumination
- Ambient lighting (with code 877 (Ambient lighting) or code 891 (Premium ambient lighting))
Additional function requirement for interior illumination after an accident
- Vehicle stationary
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.
Function sequence for interior illumination after an accident
After an accident with airbag deployment, the front SAM control unit activates the interior illumination.
The interior illumination is actuated in order 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 a crash event by evaluating the signals of the integrated crash sensor.
The front SAM control unit evaluates all incoming information and activates the following interior illumination functions:
- Locator lighting
- Search and symbol illumination
- Ambient lighting (with code 877 (Ambient lighting) or code 891 (Premium ambient lighting))
| Automatic interior lights control electrical function schematic | PE82.20-P-2052-97DCA | ||
| Overview of interior illumination (IBL) system components | GF82.20-P-9997FH |