General notes

Monitoring of light source 

Other than the following exceptions, all the light sources of the exterior lights in the switched on state are monitored by the Body Domain Controller (BDC).

• Number-plate light
• Brake light in the additional brake light

  Tail light in the rear lights in the rear apron (depending on the national-market version)

• Side marker light (depending on the national-market version)

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. If e.g. during switched on halogen headlights the power consumption of the halogen bulb cannot be measured, the Body Domain Controller (BDC) detects faulty halogen headlights. The system cancels the activation signal to the affected halogen headlights and a Check Control message appears in the instrument cluster.

Emergency operation 

LED headlight: If a fault occurs in the Body Domain Controller (BDC) which could lead to the malfunction of an LED headlight, an emergency operation is activated by the Frontal Light Electronics Left (FLEL) or Frontal Light Electronics Right (FLER).

During a fault in the Frontal Light Electronics Left (FLEL) or Frontal Light Electronics Right (FLER), an emergency operation is activated by the Body Domain Controller (BDC). However, the driving lights remain switched on until the vehicle is stopped.

Halogen headlight: If a defect that could lead to the malfunction of the entire exterior lights occurs in the software for the Body Domain Controller (BDC) the emergency operation is activated.

Emergency operation for LED headlight and halogen headlight:

• Driving light: Driving light and one tail light on each side
• Brake light: Additional brake light and one brake light on each side

The malfunction is displayed as a Check Control message in the instrument cluster (KOMBI).