Logic of naming actuators in VW-group is simple it contains "N" + actuator number. The actuator number is unique. Here you can find fitting location, connectors and some basic information about actuators.

To our mind, actuators information is reference, so there is only simple search by number.


Audi A8 4E (2002 -)
Audi A6 4F (2005- )
Audi Q7 4L (2007- )
Audi A4 8K (2008-)
Audi A3 8P (2003- )
Audi Q5 8R (2009- )

Coolant shut-off valve, heater -N279


A - Coolant hose with clamps

B - Bolt

C - Connector, heater coolant shut-off valve -N279


During operation of the additional water heater the engine coolant circuit is isolated from the heating system heat exchangers in the vehicle interior.

The isolation is effected by the coolant shut-off valve. If no voltage is applied, the coolant shut-off valve connects the coolant circuit between the heating system heat exchanger and the engine circuit. The shut-off valve is activated and the heating system heat exchanger is connected to the additional water heater. This causes the vehicle interior to pre-heat, and not the engine.


The activation is carried out directly by the additional heater control unit -J364 . On vehicles with a 4- or 6-cylinder petrol engine, the coolant shut-off valve -N279 can also be activated with the auxiliary heater off (for example at certain settings of the Climatronic control unit -J255, to shut off the coolant supply to the heat exchanger of the AC unit).


ST Important !

Risk of scalding.

The cooling system is pressurised. The coolant temperature

may be above 100 °C when the engine is warm.

Allow the pressure and temperature to drop as necessary before carrying out repairs.


A Workshop Manual; Auxiliary heater; Rep.Gr. 82.

A Current flow diagram


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