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Switching auxiliary heating/ventilation on and off > < Switching auxiliary heating/ventilation on and off via dash panel insert

A3 Mk2

Requirements
Requirements
l  To enable the control unit in dash panel insert -J285- to exchange data with the auxiliary heater control unit -J364- via the data bus system (convenience and infotainment CAN bus → Current flow diagrams, Electrical fault finding and Fitting locations), the auxiliary heater must be coded/adapted as an optional extra in the control unit for data bus diagnostic interface -J533- and in the control unit in dash panel insert -J285- → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
l  The auxiliary heater must be adapted in the control unit in dash panel insert -J285- → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
   
l  Auxiliary heater can only be switched on by control unit in dash panel insert -J285-/“Heating on” function can only be activated if:
–  There is sufficient fuel in fuel tank. With ignition on, fuel gauge -A- must not be in “red zone”.
–  There are no faults stored in auxiliary heater control unit -J364-.
–  Vehicle battery is adequately charged.
–  There are no faults in vehicle data bus system.
  A82-0377
l  The function “Auxiliary heating/ventilation”-B- must have been entered via the “Adaption” function in the control unit in dash panel insert -J285- (adaption is described in Guided Fault Finding for control unit in dash panel insert -J285-) → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
l  With ignition on, “Adjustment” menu -A- in driver information system gives access to “auxiliary heating/ventilation” function -B-.
  Note
t  Currently settings for the auxiliary heating/ventilation must be performed via the “Adaption” function in the control unit in dash panel insert -J285- → Electrical system; Rep. Gr. 01 and → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
t  Auxiliary heater must have been coded as an optional extra in control unit for data bus diagnostic interface -J533- (observe fitting list for this vehicle) → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
t  The auxiliary heater must have been adapted in the operating and display unit (Climatronic control unit -J255-) via the “Basic setting” function. The Climatronic control unit -J255- interrogates the control units fitted via the data bus system → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
t  If the “interior monitor” function responds in auxiliary heating mode, the sensitivity of the interior monitor can be altered (reduced) in the convenience system central control unit -J393- by way of the “Adaption” function → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
t  Settings of control unit in dash panel insert -J285- (for auxiliary heating mode) → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
Example:
–  Currently Audi A3 vehicles are fitted with a heater coolant shut-off valve -N279- irrespective of the vehicle model and type of engine (discontinuation on certain versions not yet finalised).
–  At the factory, the control unit in dash panel insert -J285- for vehicles with heater coolant shut-off valve -N279- is adapted so that the coolant flows in the small coolant circuit in auxiliary heating mode and auxiliary heating/ventilation remains in operation after switching off the engine → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
t  However, if required, the control unit in dash panel insert -J285- can also be adapted so that auxiliary heating/ventilation is shut off automatically when the engine is switched off → Guided Fault Finding function of vehicle diagnostic, testing and information system VAS 5051.
t  Currently the heater coolant shut-off valve -N279- is fitted on all vehicles (possible discontinuation for certain versions).
–  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). Heater coolant shut-off valve -N279- is no longer activated after engine is started.
–  On vehicles without heater coolant shut-off valve -N279-, coolant always flows via engine to auxiliary heater in auxiliary heating mode (engine is preheated in auxiliary heating mode; however passenger compartment takes longer to become warm).
  A82-0374

Switching auxiliary heating/ventilation on and off > < Switching auxiliary heating/ventilation on and off via dash panel insert