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Diverting fuel (for auxiliary heater) from fuel tank > < Activating and deactivating auxiliary heating/ventilation

A4 Mk2

Diverting fuel for auxiliary heater
Diverting fuel for auxiliary heater
  WARNING
Observe the applicable rules for cleanliness, take the appropriate precautions and heed the relevant safety measures when working on open fuel systems. → Fuel supply system; Rep. Gr.20
  Note
t  For auxiliary heater operation, the fuel pipe must be flush with the underside of the vehicle and routed so as to be protected against mechanical damage. The fuel pipe to the auxiliary heater must be protected against heat generation which could affect operation (the fuel pipe must not come into contact with vehicle components which become warm).
t  Depending on vehicle equipment there are different fuel delivery units for vehicles with and without auxiliary heater → Parts List.
   
1 - Fuel delivery unit with connection for diverting fuel for auxiliary heater
q   Removing and installing → Fuel supply system; Rep. Gr.20
q   Diverting fuel from fuel tank
q   For front-wheel drive vehicles up to 01.03 (except 2.5 l diesel engine Model Year 2002, gradual conversion) → Chapter
q   For front-wheel drive vehicles as of 01.03 (gradual conversion) → Chapter
q   For front-wheel drive vehicles (2.5 l diesel engine Model Year 2002 only, gradual conversion) → Chapter
q   For four-wheel drive vehicles → Chapter
  Note
This illustration shows the sealing flange of a vehicle with petrol engine and front-wheel drive. The layout may differ depending on vehicle model and production period → Fuel supply system, petrol engine; Rep. Gr.20, → Fuel supply system, diesel engine; Rep. Gr.20 and → Parts List
2 - Fuel pipe
q   With quick-release coupling for connection to metering pump and fuel delivery unit
q   Unfastening quick-release coupling → Chapter
3 - Metering pump -V54-
q   Removing and installing → Chapter
q   Checking fuel delivery → Chapter
q   Checking actuation → Chapter
In auxiliary heating mode, the metering pump -V54- is actuated with full voltage by the auxiliary heater control unit -J364- up to control unit part number index “B”. For control units as of part number index “C” (gradual introduction as of Model Year 2005), the voltage for the actuation signal of the metering pump -V54- will be limited in auxiliary heating mode to 9.2 V with the petrol version and 9.8 V with the diesel version, thus reducing the operating noise of the metering pump -V54-.
4 - Fuel pipe
q   Routing of fuel pipe between metering pump and auxiliary heater → Chapter
5 - Auxiliary heater
q   Different versions for vehicles with petrol or diesel engine → Chapter

   

Diverting fuel (for auxiliary heater) from fuel tank > < Activating and deactivating auxiliary heating/ventilation