Functional description

The KAFAS control unit controls the KAFAS camera heating.

The camera-based driver support systems control unit evaluates the following input variables for the switch-on conditions and switch-off conditions of the KAFAS camera heating:

• Terminal status: Terminal 15 on
• Ambient temperature

The one-time heating duration depends on the ambient temperature.

• Ambient temperature between 5 °C and 15 °C: One-time heating duration e.g. 100 seconds
• Ambient temperature below 5 °C: One-time heating duration e.g. 130 seconds

• Operation of the windscreen wiper

  Windscreen wiper activated: Depending on the ambient temperature, the heating is periodically repeated (e.g. every 300 seconds) provided the precondition is present.

• Operation of the defrost button

  Defrost function activated: The one-time heating duration for the KAFAS camera heating depends on the ambient temperature.

  Defrost function deactivated: If the one-time heating duration for the KAFAS camera heating is not yet over and there is no other precondition, the heating is deactivated.

• Operation of the button for the heated rear window

  Heated rear window activated: The one-time heating duration for the KAFAS camera heating depends on the ambient temperature.

  Heated rear window deactivated: If the one-time heating duration for the KAFAS camera heating is not yet over and there is no other precondition, the heating is deactivated.

• Temperature and air humidity on inside of the windscreen

  The condensation sensor (constituent part of the rain-light-solar-condensation sensor) detects the temperature and the air humidity on the inside of the windscreen. Depending on the ambient temperature, the heating duration is periodically repeated provided the precondition is present (e.g. above 66% air humidity).

• Battery status

The maximum temperature of the KAFAS camera heating is limited to 70 °C.

The following graphic shows a simplified representation of a KAFAS camera heating.

Courtesy of BMW OF NORTH AMERICA, INC.