Part III
Exterior Lighting
Variable light distribution
In the European market version a variable light distribution function is also integrated in the footwell module (FRM). The variable light distribution includes the following distribution patterns:
- City light distribution
- Country road light distribution
- Motorway light distribution
- Guiding fog light
The variable light distribution is not available in US market versions.
City light distribution
The urban light distribution pattern projects more light toward the left edge of the road than the previous lighting system. The footwell module (FRM) implements the improved roadway illumination with the following measures:
- Lowering the left headlight
- Tilting the left headlight to the left
The urban light distribution pattern is available as soon as the "engine running" signal is present. The Digital Engine Electronics (DME) and Digital Diesel Electronics (DDE) furnish the signal. The footwell module (FRM) receives the "engine running" signal via K CAN2.
Country road light distribution
The secondary road light distribution pattern corresponds to the pattern hitherto employed for the driving light. This lighting function is available once "Terminal 15 on" status is present. The country road light distribution represents the basic setting for the headlights. The basic setting is assumed when there are faults in the complete light distribution system.
The system switches from urban traffic light distribution to country road light distribution as soon as the driving speed exceeds 45 kilometres per hour. The system reverts to the urban light distribution pattern when the driving speed falls back below 40 kilometres per hour. The footwell module (FRM) receives both the speed signal and the "engine running" signal from the central gateway module (ZGM) via K CAN2).
Motorway light distribution
The footwell module (FRM) adjusts the headlights to motorway light distribution under the following preconditions:
- Driving speed exceeds 110 kilometres per hour for longer than 30 seconds
- Driving speed exceeds 140 kilometres per hour
The headlights are lowered once the driving speed falls below 110 kilometres per hour.The headlights are lowered (reducing the headlight beam throw) in gradual stages as the speed drops below 110 kilometres per hour:
- 110 kilometres per hour
- 100 kilometres per hour
- 90 kilometres per hour
- 80 kilometres per hour
From 80 kilometres per hour, the headlights are fully reset to country road light distribution.
Automatic headlight beam throw adjustment
The automatic headlight beam throw adjustment thus ensures that oncoming traffic is not dazzled.The automatic headlight beam throw adjustment is supported by two ride height sensors.Automatic headlight beam throw adjustment is legally mandated for bi-xenon headlights.
The automatic headlight beam throw adjustment also includes:
- Dynamic headlight beam throw adjustment
- Adaptive headlight beam throw adjustment
The dynamic headlight beam throw adjustment was developed for compensating pitching movements that occur as a result of braking and acceleration.
Adaptive headlight beam throw adjustment uses driving condition signals to identify driving over rises or dips.The headlights are turned appropriately. The automatic headlight beam throw adjustment thus ensures that oncoming traffic is not dazzled.
The automatic headlight beam throw adjustment is supported by 2 ride height sensors. one ride height sensor each located on the front axle and the rear axle of the vehicle. Data from ride height sensors are evaluated directly by the Integrated Chassis Management (ICM). The footwell module (FRM) receives signals from the Integrated Chassis Management (ICM) through the K-CAN2. Within the central gateway module (ZGM) the FlexRay transfers the signal to the K-CAN2.
The following graphic shows the light cone's primary motion patterns during operation of the automatic headlight beam throw adjustment.
The headlight is increased while driving through a dip. The driving area visibility is enhanced without blinding oncoming traffic. Roadway obstacles are recognised earlier than with previous headlight systems. This makes it possible to react to obstacles early and initiate evasive manoeuvres as required.
The following illustration shows vehicle driving through a dip.
The headlight beam throw is lowered when driving over a rise. The driver of an approaching vehicle is subjected to less glare than with the headlight systems used up to now.
The following illustration shows vehicle driving over a hump.
High-beam assistant
When activated with the headlights on, the high-beam assistant automatically activates and switches off the high-beam headlights. A sensor mounted on the front of the inside mirror controls this process. The high-beam assistant ensures that the high-beam headlights are activated whenever traffic situations allow.
The high-beam headlights can always be switched on and off manually.
To activate the high-beam assistant:
1. Turn light switch to "AUTO Position"
2. Press the high-beam assistant button on the left steering column switch
The indicator light in the instrument cluster lights up.
The high-beam assistant responds to lights on approaching and preceding vehicles while also monitoring the surrounding area for adequate illumination.
Manual high-beam activation and dipping
1. High-beam headlight on or headlight flasher on
2. High-beam headlight off
To switch the high-beam assistant off, press the high-beam assistant button on the left steering column switch again.
Limits of the system
The high-beam assistant does replace the individual's responsibility to decide when the high-beam headlights are used. Thus the headlights must be dipped manually whenever conditions render it necessary to do so.
Operation of the high-beam assistant is restricted, or it may fail to operate entirely, under the following conditions:
- Unfavourable weather conditions, such as fog or heavy precipitation
- Road users with poor lighting
- Sharp curves, steep rises and dips
- Crossing traffic or partially hidden traffic on the opposite side of motorways
- Poorly lit towns and intense reflections from road signs
- Low driving speed
- Condensation, contamination or stickers on windscreen in the area around the inside mirror
Sensor field of view
The sensor's field of view starts on the front side of the inside mirror. The area in front of the inside mirror must not be obstructed by air fresheners, etc.
Turn indicator
The front and rear turn indicators and the side-mounted turn indicators are available for activation as soon as "Terminal R" is under power. The turn indicators are operated by the turn signal/high beam switch on the steering column switch cluster (SZL). The signal from the turn signal/high beam switch is transmitted both via FlexRay protocol and through a separate line to ensure functional redundancy. This increases system availability in the event of a fault. The turn indicator light remain operational even when the information fails to reach the footwell module (FRM) through the bus system. This redundant data-transmission is also employed for activating the one-touch flashing function.
A fault with the front or rear turn indicators will cause the turn indicators to flash at twice their usual rate. All turn indicators are equipped with light-emitting diodes.
During one-touch flashing the turn indicators are activated once. The number of flashes can be set to once or three times in "Personal Profile".
A visual and acoustic indication of turn indicator status is supplied by the instrument panel (KOMBI). The footwell module (FRM) transmits the information to the instrument panel (KOMBI) via the K-CAN2, and the instrument panel responds by activating the acoustic sensor and the indicator lights simultaneously with the turn indicators. The acoustic signal and visual display in the instrument panel (KOMBI) are deactivated when the vehicle's central locking system is engaged while the hazard warning flashers are operating.
Hazard warning flashers
The hazard warning flashers are activated by pressing the hazard warning switch. All turn indicators are activated simultaneously while the hazard warning switch display within the instrument panel (KOMBI) also flashes.
With "Terminal 30 on" the hazard warning flashers are implemented in their energy-saving mode. In this mode, the hazard warning flashers light up for a shorter period and remain off for a longer period than usual.
When the turn signal/high beam switch is used to activate the turn indicator light while the hazard warning flashers are operating, the turn indicator light assumes priority. The system reverts to operation of the hazard warning flashers after "Terminal 15 off" or when the turn indicator light has returned to its original position.
If the hazard warning switch is depressed while the turn indicator light is operating, then the hazard warning flashers assume priority.
Hazard warning flashers during dangerous or emergency braking
The hazard warning flashers are automatically activated and then deactivated following emergency or dangerous braking.
Hazard warning flashers when anti-theft alarm system triggers alarm
When an alarm is triggered, the footwell module (FRM) receives the command to activate the hazard warning flashers via K CAN2. The signal is generated by the ultrasonic interior movement detector. The hazard warning flashers continue for 6 minutes provided that the anti-theft alarm system is not switched off in the intervening period. When the anti-theft alarm system is signalling an active alarm the hazard warning switch is suppressed and does not flash with the alarm system. The ultrasonic interior movement detector is completely integrated within the roof function centre (FZD).
Brake light
At "Terminal 15 on" status the brake light can be activated by the brake-light switch. The Car Access System (CAS) furnishes the brake-light switch with a 5-volt voltage supply. The Car Access System (CAS) processes the status of the brake-light switch and transmits it through K CAN2. The footwell module (FRM) receives the status in this process and responds by activating the brake lights.
The signal from the brake-light switch is also employed by the dynamic headlight beam throw adjustment.
The brake light can also be activated by Dynamic Brake Control, such as the Active Cruise Control with Stop&Go function.
Dynamic brake light for European national-market versions
In Europe, a new regulation prescribing dynamic brake light featuring an "emergency stop" signal is now in effect. The signal consists of:
- Flashing brake lights
- Activation of the hazard warning flashers
Operation of the dynamic brake light is divided into several phases:
- Normal braking
- Dangerous or emergency braking
- Activation of the hazard warning flashers
- Resetting the hazard warning flashers
Normal braking
The footwell module (FRM) receives the signal from the brake-light switch directly. The brake lights are activated. The deceleration rate lies between 0 and 6 metres per second2.
The braking deceleration is monitored by wheel speed sensors. The Dynamic Stability Control (DSC) system transmits the wheel speed signals to the Integrated Chassis Management (ICM). The Integrated Chassis Management (ICM) then calculates the progression of the deceleration process as well as the speed. The Integrated Chassis Management (ICM) transmits the information over the FlexRay system. The central gateway module (ZGM) transfers this information to K CAN2. By this route the footwell module (FRM) receives the information for subsequent processing and analysis. The analysis is employed in generating the signals that control activation of the brake lights.
Dangerous or emergency braking
The brake lights change from continuous lighting to a pulsed flashing mode under the following preconditions:
- Dangerous or emergency braking of sufficient duration
- Deceleration rate in excess of 6 metres per second2
- Closed-loop control intervention from the Antilock Braking System (ABS)
The brake lights then receive a control signal with a frequency of 5 hertz. The dynamic brake light functionality can be implemented at speeds of more than 50 kilometres per hour.
Activation of the hazard warning flashers
The brake lights revert from their pulsed flashing mode to continuous lighting under the following preconditions:
- Deceleration rate falls below 2.5 metres per second2
- Driving speed drops below 20 kilometres per hour
The hazard warning flashers are automatically activated at the same time. This serves as supplementary warning source for following traffic.
Resetting the hazard warning flashers
When the vehicle comes to a standstill, the hazard warning flasher remains on until the vehicle accelerates again or the hazard warning flashers are switched off manually.
Dynamic braking lights decoding
Legal regulations in some countries prohibit flashing brake lights, which are therefore not included in the national-market versions for these countries. The "dynamic brake light" function is encoded to remain inactive in national-market versions destined for sale in these countries.
Brake Force Display (US national-market version)
The Brake Force Display is fitted to vehicles for the US national-market version. Progress of the braking process is signalled by a corresponding enlargement of the surface area illuminated by the brake light. Flashing of the red surfaces on the brake light is not approved.
The Brake Force Display function operates under the following preconditions:
- Driving speed greater than 5 kilometres per hour
- Braking deceleration exceeds 5 metres per second2
- Closed-loop control intervention from the Antilock Braking System (ABS)
Reversing lights
The reversing light is switched on after "terminal 15 ON" when reverse gear is engaged. The footwell module (FRM) receives the signal for this process through K-CAN2. The electronic transmission control (EGS) makes this signal available on the K-CAN2 in vehicles fitted with an automatic transmission.
The signal is provided by the reversing light switch in vehicles with a manual gearbox. The reversing light switch is connected to the footwell module (FRM) by a line. When reverse gear is engaged, the footwell module (FRM) switches the reversing lights on.
Rear fog light
The rear fog light (European market version) can be switched on provided that compliance with the following preconditions is present:
- "Terminal 15 on"
- "Driving light on"
- Rear fog light button depressed
Press the rear fog light button a second time to switch off the rear fog lights. If the light switch is turned to "Position 0" while the rear fog light is on, then the fog light will be deactivated automatically.
Parking light
The turn signal/high-beam switch can be used to activate the side lights whenever the status "Terminal 30 on" is present. The turn signal/high beam switch must be pressed to the left or right position for longer than half a second. This time delay prevents the parking lights from being switched on inadvertently, for instance, when the driver brushes against the turn signal/high beam switch when exiting the vehicle.
The footwell module (FRM) implements the side lights function by switching on the side lights and the tail light on the selected side of the vehicle. The footwell module (FRM) receives the command requesting activation of the side lights from the steering column switch cluster (SZL). The central gateway module (ZGM) transmits the signal to K CAN2.
Visual feedback signal from central locking system
The factory setting for the central locking system's visual feedback signal is the flashing of the turn indicators upon activation. The Car Access System (CAS) furnishes the signal through K CAN2. The visual feedback signal can be deactivated in "Personal Profile". The anti-theft alarm system can also initiate visual feedback signals for the customer.
Emergency lighting with "Terminal 15 off"
The exterior lights would be switched off in the following driving situations:
- "Terminal 15 on" ceases to be valid
- Accidental pressure on the start/stop button
If the driving lights are on they remain on under these conditions in order to ensure continued traffic safety. Once the driving speed falls to below 20 kilometres per hour the driving lights are switched off with a time delay of approximately 30 seconds.
Notes for Service department
Adjust headlight.
The headlight adjustment can be changed using the same procedure employed up to now. On vehicles equipped with the optional Adaptive Headlight, the light switch must be in "Position 2". When the lights are switched on by the automatic driving lights control, the urban light distribution pattern is active. The headlights can only be correctly adjusted in the country road light distribution mode.In the urban traffic light distribution mode, the left headlight is simultaneously lowered and swivelled slightly to the left.If the headlights are adjusted while in their urban light distribution mode, the automatic driving lights control will dazzle oncoming traffic. This is why the headlights should always be adjusted with the switch in "Position 2".
Ensure that only original BMW parts are used when renewing the headlights. The repair instructions must be followed without exception.
Right-hand traffic and left-hand traffic
The headlights have been designed for both left-hand right-hand traffic. This means that it is possible to continue driving without any special measures when crossing a border into a country in which vehicles drive on the opposite side of the road from the country in which the vehicle is registered. However, the light switch must be turned to "Position 2".
Renewing components.
Various repairs may be necessary over the service life of the vehicle. In the course of repairs, components for various software versions and hardware numbers may be installed. New parts are then used together with components already installed in the vehicle. It is always essential to adapt the replacement components for operation in the vehicle. Among the components that may be replaced when the vehicle is serviced are the:
- Footwell module (FRM)
- Headlight driver module
- Light source
- Headlight
- Rear light
Refer to the appropriate repair instructions for more details.
Footwell module (FRM)
The repair instructions must be followed for renewing the footwell module (FRM). Ensure that only original BMW parts are used. Only original BMW parts guarantee the exterior lights function. When the footwell module (FRM) is swapped with another module, it is possible that malfunctions of the exterior lights will result.
LEDs
Apart from the lighting ring, all LED components in the exterior lighting can only be replaced in their entirety.
Diagnosis
The exterior lighting must be set to the "diagnostic mode" as a condition for carrying out various diagnosis orders.
For example, the "diagnostic mode" is required for the following diagnosis orders:
- Reading out relevant bus signals while the vehicle is stationary
- Vehicle speed
- Yaw rate
- Steering angle
- Analysis of switch-on conditions
- Status of rain-light-solar-condensation sensor.
- Status of high-beam assistant
- Status of light switch
When expected bus signals are not received and when they are classified as implausible a corresponding diagnostic trouble code (DTC) is logged in the footwell module (FRM).
The types of faults are stored in the headlight driver module. The footwell module (FRM) provides access to the headlight driver module.
General notes
Monitoring of light source
All of the exterior lighting's light sources are monitored by the footwell module (FRM) when switched on. Monitoring starts at "Terminal 15 ON".
Hot monitoring at "lights on"
Hot monitoring is based on the current measurement. The power consumption readings assist in detection of short and open circuits. Thus, if the power consumptions of the gas discharge bulbs cannot be measured while the bi-xenon headlights are switched on, the footwell module (FRM) identifies a faulty bi-xenon light. The system cancels the activation signal to the affected bi-xenon light and a Check Control message appears in the instrument panel's display panel.
The monitoring function also embraces the light-emitting diodes in the exterior lighting. This function relies on monitoring of power consumption. Failure of light-emitting diodes is also indicated as a Check Control message in the instrument panel (KOMBI).
Emergency operation
If a defect that could lead to failure of the entire exterior lighting occurs in the software for the footwell module (FRM) the emergency operation is activated:
- Driving light: Driving light and one tail light on each side
- Brake light: Additional brake light and one brake light on each side
We can assume no liability for printing errors or inaccuracies in this document and reserve the right to introduce technical modifications at any time.