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Incorporation of auxiliary heater on vehicles with heater coolant shut-off valve N279 > < Auxiliary heater temperature control curve

A3 Mk2

Incorporation of auxiliary heater into coolant circuit
Incorporation of auxiliary heater into coolant circuit
  Note
t  Vehicles with a diesel engine manufactured since the start of production and fitted with an auxiliary heater as an optional extra are also fitted with an additional electric heater → Heating, air conditioning; Rep. Gr.87. To prevent simultaneous activation of both additional heating systems, attention is to be paid to the adaption of the auxiliary heater control unit -J364- → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
t  If vehicles with a diesel engine are fitted with an auxiliary heater as an optional extra, this will in future also be activated as additional heater (no additional electric heater fitted, discontinuation not yet finalised) → Heating, air conditioning; Rep. Gr.87.
t  For all components not mentioned, refer to → Engine, mechanics; Rep. Gr. 19; Cooling system.
t  Currently the auxiliary heater is not activated as an additional heater on vehicles with petrol engine.
t  The hoses between the engine and the auxiliary heater differ depending on the engine version → Engine, mechanics; Rep. Gr. 19; Cooling system.
t  At start of production, heater coolant shut-off valve -N279- is fitted on all vehicles (however, this may be discontinued for certain versions in the future depending on engine and vehicle equipment).
t  On vehicles with heater coolant shut-off valve -N279-, coolant flows directly back to auxiliary heater from heat exchanger of air conditioning unit when auxiliary heating mode is switched on and engine is not running (engine is not preheated in auxiliary heating mode; entire heat energy generated by auxiliary heater is supplied to passenger compartment).
t  On vehicles without heater coolant shut-off valve -N279-(time for discontinuation not yet finalised), coolant always flows via engine to auxiliary heater when auxiliary heating mode is switched on (engine is preheated in auxiliary heating mode; however passenger compartment takes longer to become warm).
   

Incorporation of auxiliary heater on vehicles with heater coolant shut-off valve N279 > < Auxiliary heater temperature control curve