General Information
Interior Lighting
Purpose of the System
The GM controls the interior lighting automatically with the status change of several monitored inputs. The lighting can also be manually controlled using the interior light switch.
In addition to the various time controls, the interior lights are also subject to the 16 minute shut down of the GM (consumer protection).
Principle of Operation
The interior light switch is a push button switch that will carry out the opposite command of the current status of the lights. (ie: if the interior lights are currently on, pushing the button will switch the lights off.)
- If the interior lights are switched "ON" by the button with the ignition switched ON, the interior lights will remain on until they are switched off by the button.
- If the interior lights are switched "ON" when the ignition is switched OFF, the lights will remain on for 16 minutes (consumer cutout).
- Pressing the interior light button for longer than three seconds will switch the lights to continuous off. This feature is intended for workshop use. Pressing the button again will return the lights to the normal operational status.
- Locking the vehicle from the outside will immediately switch off the interior lights.
The ON/OFF conditions for the interior lights in the automatic mode are as follows:
ON Conditions
- Door Open.
- Switching off ignition after exterior lights have been switched off.
- MRS Control Module crash input.
- Unlocking with FZV or pressing FZV lock button when the vehicle is already locked (interior search function).
OFF Conditions
- All doors closed with ignition on.
- All doors closed with ignition off after 20 seconds.
- 20 seconds after switching off ignition with lights off.
- 8 seconds after remote control activation.
- 16 minutes with door(s) open When doors are locked.
System Components: Inputs - Processing - Outputs
System Components
Door Contacts
As mentioned in the Central Locking Section, the existing door contacts opened/closed are also an input for the interior lighting function. The E53 uses the Hall effect sensors for the purpose of monitoring door open/closed status (located directly behind the rotary latch plate encased in the actuator). The sensor is activated by the rotary latch plate's position.
- Door closed, the rotary latch plate is in the latched position. Current flaw through the hall sensor is < 5 mA.
- Door open, the rotary latch plate is in the open position. Current flow through the hall sensor is > 12 mA.
A change in current flow informs the General module when a door is opened or closed.
Front Seat Interior/Map Light Unit
The overhead front seat interior light unit contains a single main interior light. The light is controlled by the GM automatically or by momentarily pressing interior light switch located on the light assembly.
The switch provides a momentary ground signal that the GM recognizes as a request to either turn the light on (if off) or turn the light off (if on).
If the switch is held for more than 3 seconds, the GM interprets the continuous ground signal as a request to turn the interior light circuit off for the Workshop Mode.
The workshop mode is stored in memory and will not come back on even if the GM is removed from it's power supply and reconnected. The switch must be pressed to turn the lights back on.
There are two reading/map lights also located in the assembly. Each map light is mechanically controlled by depressing the corresponding on/off switch. The power supply for the map lights is supplied by the GM through the Consumer Cut Off circuit.
Rear Seat Interior/Reading Light Units: In each C pillar trim panel is an interior/reading light unit.
These units each contain an interior light that is controlled with the front interior light and a mechanically switched reading light on the consumer cut off circuit.
Front Footwell Lights: In each front footwell, there is also a courtesy light. These lights are only operated when the GM provides power to the interior lighting circuit.
On E38 and E53 the doors also contain courtesy lights at the lower edge of the door panel (1).
Door Warning Lights (E38): The additional "red" warning lights are installed in the edge of the doors (2). These lights are illuminated when the doors are opened.
Illuminated Transmission Shift Indicator (E38): The E38 uses a microprocessor for displaying the shifter position in the center console.
The processor receives shift position signals from a console mounted range switch. The processor illuminates the LED corresponding to the position of the range selector.
The park position LED will remain "on" after the ignition is switched off and stay on until the GM goes into the "sleep" mode.
Soft Lighting Feature: The GM provides progressive voltage (up to 12v) providing the soft on feature to the interior lighting circuit when the interior lights are required. The GM gradually reduces the full 12 volt power supply providing soft off when interior light deactivation is required.