Structure and inner electrical connection
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2017 BMW X3, 2016 BMW X3, 2015 BMW X3, 2014 BMW X3, and 2013 BMW X3. However, it is still accessible from the selected car via links, so may be relevant.
The drive of the electric fan is a brushless motor. The electric fan has its own electronic evaluation unit and its speed is regulated by a pulse-width modulated signal. The pulse duty factor in the normal operating mode (100 Hz) is converted into a speed signal.
- 7% pulse duty factor: Standby mode (electronic evaluation unit is kept awake)
- 11% pulse duty factor: minimum fan speed (33 % of rated speed)
- 93% pulse duty factor: maximum fan speed
- 97% pulse duty factor: command for self-diagnosis of the electronic evaluation unit
| Item | Explanation |
|---|---|
| 1 | Evaluation electronics |
| 2 | Drive for electric fan |
PIN REFERENCE
| Pin | Explanation |
|---|---|
| Terminal 31L | Load ground |
| Terminal 87 | Battery voltage terminal 30 via radiator fan cutoff relay |
| PWM | Pulse-width modulated signal |