Radiator Blind Drive

Radiator Blind Drive

Radiator blind drive
An active air flap control via actuator motor (radiator shutter drive) is installed in the front end.
Active air flap control regulates the air supply for the engine and assemblies cooling system by only opening the radiator shutter as it is needed.

Functional description
The engine control system continuously calculates the required cooling. The engine control system only opens the radiator shutter when a higher level of cooling air is actually required.
While the vehicle is being driven, the closed radiator shutter reduces the warm-up phase of the engine, as operating temperature is reached more quickly if the environment is better encapsulated. The air flow through the radiator creates high aerodynamic drag as the driving speed increases. In higher road speed ranges, the closed radiator shutter improves the aerodynamics. This reduces fuel consumption and thus the emission value.







Structure and inner electrical connection
The radiator blind drive is a direct current motor. The engine control system is connected via LIN bus (Local Interconnect Network bus) to the radiator blind drive.
The radiator shutter drive is activated via a pulse-width modulated signal (PWM signal) from the engine control system. The radiator shutter has 2 positions: opened and closed. The radiator blind drive is supplied with voltage via the junction box.







Switch-on conditions and setpoint values
The following evaluation criteria are used for the air flap control:
- Coolant temperature (coolant-temperature sensor and temperature sensor at the radiator outlet, if present)
- Gearbox oil temperature
- Engine oil temperature
- Current supply to the characteristic map thermostat (if present)
- Load signal
- Engine speed
- Driving speed
- Speed of the electric fan
- Trailer detection

Observe the following nominal values for the radiator shutter drive:

Size Value
Voltage range 9 to 16 volts
Frequency pulse width modulation 180 to 220 Hz
Maximum power consumption 2.2 A
Temperature range -40 to 120 °C

Diagnosis instructions

Failure of the component

If the radiator shutter drive fails, the following behaviour is to be expected:
- Fault entry in the engine control unit

General notes
The radiator shutter drive remains in the position it was in when the fault occurred.
The radiator shutter lock is also deactivated if a defect is detected at the coolant-temperature sensor or electric fan.
We can assume no liability for printing errors or inaccuracies in this document and reserve the right to introduce technical modifications at any time.