Radiator shutter

The radiator shutter seals off the engine compartment from the outside and directs the cooling air under the engine.

When the vehicle is driven, the closed radiator shutter reduces the warm-up phase of the engine. In higher road speed ranges, this improves the CW value of the vehicle. This saves fuel and thus has an advantageous effect on the emissions. Furthermore, the faster heating of the coolant means that the full heat output of the vehicle can be called up earlier.

Components

• Radiator shutter
  
• Solenoid switch
  

Function

With the ignition off or in the event of a break in the activation cable, the radiator shutter is not locked. After engine start-up, the engine control unit switches the solenoid switch to earth and thus closes prevents the radiator shutter from opening.

When one or more of the following conditions exist when the vehicle is being driven, the magnetic lock for the radiator shutter is deactivated.

• Coolant temperature > 90°C
  
• Gearbox fluid temperature > 110°C
  
• Engine oil temperature > 130°C
  
• Power to map thermostat > 90% (only DME)
  
• Electric fan active
  

Fault code memory entries

If there is an electrical fault in the assembly, the radiator blind lock is deactivated.

The radiator shutter lock is also deactivated if a defect is detected at the coolant-temperature sensor or electric fan.