Side lights, parking lights

Side lights and parking lights are legally prescribed functions for lighting up the parked vehicle.

• In the side lights switch position, both sides of the vehicle are lit up.
  
• The parking light lights up only the side of the vehicle selected using the turn indicator-low beam switch (after ignition OFF).
  

Brief description of components

Light switch

The light switch consists of

• Rotary switch for side lights and low beam as well as Automatic Light Control (FCL) with light emitting diode FLC for driving light control
  
• Button for rear fog light
  
• Potentiometer for dimmer of panel illumination
  

The rotary switch for side lights and low beam has two switch contacts. Depending on the status of the two switch contacts, the light module can detect four switch positions:

S_SL = interior switch for side lights

S_AL = interior switch for low beam

1 = interior switch closed (after 5 V)

0 = interior switch open

Power supply: The switch is supplied with 5 Volts by the light module.

If the power supply is defective, the light remains ON: the light is automatically switched on if

• the cables to and from the light switch have been cut or
  
• are switched to ground
  
• are at 12 V.
  
• For safety reasons, the light switch can only be switched OFF if there is 5 V at both switch outputs to the light module. If a short circuit means that there is once 5 V and once 12 V, the light can not be switched OFF: low beam and Automatic Light Control remain ON.
  

Turn indicator-low beam switch

The steering-column lever to the left of the steering wheel switches the functions

• Turn indicator (one-touch flashing or continuous flashing left or right) with terminal R On,
  
• Parking light left or right: with terminal R OFF, overpress the switch beyond the engaging point, as for continuous flashing.
  
• High beam and headlight flasher.
  

The steering-column lever does not engage in the switch positions. The functions are operated by

• Touching the switch to move it forwards or backwards: high beam and low beam
  
• Touching the switch to move it to the right or left: one-touch indicating
  
• Overpressing the engaging point: continuous flashing
  

If the driver operates the steering-column lever

• a message is transmitted to the light module. Signal path: SZL (steering column switch center) -> data bus BYTEFLIGHT -> SIM (Safety and Information Module) -> data bus BYTEFLIGHT -> ZGM (Central Gateway Module) -> data bus K-CAN SYSTEM -> LM (Light Module).
  
• At the same time, the light module evaluates a direct signal from the steering-column lever. This signal is transmitted across a separate cable, making it independent of the K-CAN SYSTEM data bus.
  

Function limitation in the case of failure of the data buses:

• High beam and headlight flasher only run if the steering-column lever is held.
  
• The indicator light only runs if the steering-column lever is held. no continuous flashing, no automatic reset
  
• No hazard-warning lights in the event of a crash and when arming the antitheft alarm.
  

Light module

The light module controls and monitors the vehicle lights. Information is received and sent via the data bus K-CAN SYSTEM.

The faults of the xenon headlights are evaluated in the light module.

Emergency operation properties of the light module: The light module is supplied with terminal 30 twice.

If a terminal 30 fails, the following are activated:

• Front lighting: low beam and parking light (each on one side).
  
• Tail lighting: On one side, the outer side lights/brake lights are activated (parking light). On the other side, the inner taillights are activated. The vehicle thus still has lights on both sides. Confusion with a one-track vehicle (motorcycle) is excluded.
  
• Brake light: One side of the brake lights is activated with normal power (ECE coding).
  

In the case of a failure of the processor, emergency operating mode is activated. Emergency operating mode involves hardware that is completely independent of the light module. Emergency operation properties with failure of the processor:

• Vehicle lighting: At terminal 15 On, the following are switched on: Front low beam and rear side lights / brake light lamps left and right. The side lights / brake light lamps left and right are not, as would be normal, dimmed to 10% of their brightness, but operated with full power. This ensures the function of the vehicle lighting irrespective of the position of the light switch.
  
• Brake light: With terminal 15 On, the left and right brake lights are switched on when the brake light switch is operated (via a hard-wired, direct line from the brake light switch to the lamp drivers).
  

Function defects with failure of the processor:

• No turn indicators and hazard warning lights, no high beam, no headlight flasher, no rear fog light, no third brake light
  
• No communication across the K-CAN SYSTEM.
  

Side lights, front

The front side lights are filament bulbs. The lamps are monitored by the light module.

Inner taillights, left and right

The inner taillights left and right are light emitting diodes (LEDs). The light emitting diodes are activated with 10% of their power. The light emitting diodes are not monitored by the light module.

Side lights / brake light lamps left and right

The side lights / brake light lamps left and right are light emitting diodes (LEDs). The LEDs are not monitored by the light module.

The side lights / brake light lamps left and right also serve as brake lights (depending on coding or country variant):

• Function of taillight: the light emitting diodes are activated with 10% of their power.
  
• Function of brake light: in the case of strong braking, the light emitting diodes are activated at full power (depending on coding and/or country variant).
  

License plate light, left and right

The license plate lights are filament bulbs. The lamps are monitored by the light module.

Country-specific version

USA

In the USA, additional side markers are fitted:

• The front side markers are lamps. The lamps are monitored by the light module (on output for both lamps).
  
• The rear side markers are light emitting diodes (LEDs). The LEDs are not monitored by the light module.