Passive and active air flap control

Depending on the model series and model year, the passive and active air flap control is activated either via the LIN bus or a power output from the engine management system.

• Active and passive air flap control via power output from the engine management system

  The radiator shutter drive is activated via a pulse-width modulated signal (PWM signal) from the engine management system (DME or DDE). The radiator shutter drive is supplied with voltage via terminal 87.

  At the request of the engine management system, the electromagnet is switched on by a switch signal from the control electronics circuit. The control electronics circuit is integrated in the radiator shutter drive.

Fig 1: Active Air Flap Control - Circuit Diagram

Courtesy of BMW OF NORTH AMERICA, INC.

• Active and passive air flap control via LIN bus

  The radiator shutter drive is activated via the LIN bus by the engine management system (DME or DDE). The radiator shutter drive and electromagnet are supplied with voltage via terminal 15N.

  The electromagnet is activated directly by the engine management system.

Fig 2: Radiator Shutter Drive - Circuit Diagram

Courtesy of BMW OF NORTH AMERICA, INC.