BMW 7 Series: Functions

Important Control Units in the Interior Lighting System

The interior lighting on the F01/F02 is switched on and off by the footwell module (FRM).

The roof function center (FZD) is responsible for the interior lighting components in the passenger compartment roof.

The paragraphs that follow now describe the interior lighting functions in more detail.

Footwell Module

The footwell module is the central control unit for the interior lighting system. All interior lighting outputs of the footwell module are pulse-modulated. This ensures the interior lighting functions at a constant brightness level in the event of voltage fluctuations. The pulse width modulation is additionally used for the soft ON/soft OFF function.

The footwell module features the following functions for the interior lighting:

• Switching the interior lighting on/off
• Electric load shut-down after >8 minutes
• Lighting via terminal 58g.

Switching on the interior lighting

The footwell module receives numerous input signals that switch on the interior lighting. The input signals are read directly by the footwell module or are received via the KCAN2. The input signals for the interior lighting are listed in the following.

CENTRAL LOCKING INPUT SIGNALS REFERENCE CHART

Switching-on conditions

If any of the following conditions for switching on the interior lighting is met, the interior lighting is switched on. The switch-on function is limited in terms of time. The electrical loads are:

• Unlock via barrel lock in driver's door
• Vehicle unlocked using ID transmitter
• Terminal 15 OFF if Terminal 58g was ON no more than 2 min previously
• Lock button on ID transmitter pressed after the central locking has been in double-locked status for longer than 10 seconds.

The interior lighting remains permanently switched on in certain situations. These situations are:

• Receiving crash signal
• Interior lighting button briefly pressed.

NOTE: Pressing the interior lighting button again switches it off.

Switching off interior lighting

The footwell module receives numerous signals to switch off the interior lighting. Those signals are received via the K-CAN2 or are read directly by the footwell module.

Switch-off conditions

The interior lighting is switched off under the following conditions:

• Central locking in central arrest, all doors and the tailgate are closed
• 8 min after Terminal 15 OFF (cut-out of electrical equipment)
• Interior lighting button pressed for longer than 3 seconds (continuous "OFF")
• Terminal 15 ON when doors closed
• Terminal 58g ON and Terminal 15 OFF. The interior lighting is switched off if no door is opened within 20 seconds.
• The interior lighting is switched off if the vehicle is unlocked via the ID transmitter and no door is opened within 20 seconds.
• "Power down" via diagnosis.

Cut-out of electrical equipment

As of Terminal 15 OFF, the interior lighting is switched off by the footwell module after 8 min. For that purpose, the footwell module broadcasts the electrical equipment cut-out instruction via the K-CAN2.

The roof functions center FZD receives this information and switches off the interior lighting in the roof area.

The interior lights that are switched on directly by the footwell module are also switched off.

Terminal 58g

The footwell module supplies the Terminal 58g signal via the K-CAN2 or conventional wiring. Terminal 58g is pulse width-modulated and features the following two brightness levels:

• The brightness level for the locator lighting is individually adjustable using the thumb wheel on the lights operating unit.
• The brightness level for the function lighting is not dimmed and is switched on at full brightness.

Hazard warning switch

As soon as the hazard warning switch is pressed, the footwell module switches on the switch lighting at full brightness.

NOTE: The hazard warning switch is not illuminated at full brightness level at terminal 58g. The brightness depends on the setting of the locator lighting.

Roof Function Center

The roof function center (FZD) incorporates the front interior light unit.

The FZD is the link to the interior light unit in the rear passenger-compartment roof.

Interior lighting functions

The interior lighting functions in the roof functions center are:

• Loop-through of power supply provided by the footwell module, e.g. IB and Terminal 58g
• Reading of signals from rear reading light buttons
• Power supply to vanity mirror lights or reading lights in the rear interior light unit.

Reading of signals from rear reading light buttons

The roof function center reads the signals from the rear reading light buttons. A flip-flop circuit is used for the purpose for each rear reading light button. Pressing the reading light button changes the status of the flip-flop circuit. The change of status causes the roof function center to switch the reading light concerned on or off accordingly.

The footwell module supplies the Terminal VA status signal. The rear reading lights are among the devices switched off by the electrical equipment cut-out function.

Luggage Compartment Lighting

The luggage compartment lighting is connected directly to Terminal 30B.

The luggage compartment lighting is functional as of status Terminal 30B ON and fused in the rear power distribution box.

When the tailgate is opened, the status of the tailgate switch changes. This means the luggage compartment lights are connected to ground and therefore switched on.

The status of the tailgate switch changes when the tailgate is closed again. The ground connection is interrupted and the luggage compartment lighting switched off.

Glove Compartment Lighting

The light is connected to Terminal 30B in the front power distribution box and protected against short circuits by a fuse.

When the glove compartment is opened, the glove compartment switch closes. As a result, the glove compartment lighting is connected to ground.

The glove compartment lighting is switched off by closing the glove compartment.

Car Access System

The Car Access System supplies the central vehicle has been locking status signal via the K-CAN2. In this way, the footwell module recognizes when the unlocked and consequently switches on the interior lighting.

Courtesy Lighting

The courtesy lighting operates in sync with the interior lighting. That means that the courtesy lighting remains switched on as long as the interior lighting is on.

NOTE: Previously, the courtesy lighting was limited to 20 seconds. This functional feature on the F01/F02 is a change from other BMW models.

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