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Display groups "023” to "025” > < Display group "021”

A4 Mk2

Display group “022”
Display group “022”
Input signal from service installed auxiliary heater, activation signal for auxiliary heating or auxiliary ventilation from control unit in dash panel insert -J285-, activation signal for fresh air blower from auxiliary heater and remaining auxiliary heating/auxiliary ventilation ON time calculated by operating and display unit, Climatronic control unit -J255-
   
Display zoneSignificanceExplanatory notes
1Display zone not used
–  Intended for service installed auxiliary heater activation signal
 
 
t  Display = “Off”
–  No auxiliary heater signal
–  Voltage at connector “D”, contact “10” to operating and display unit, Climatronic control unit -J255- less than 5 V
 
t  Display = “On”
–  Auxiliary heater activation signal being applied
–  Voltage at connector “D”, contact “10” to operating and display unit, Climatronic control unit -J255- greater than 5 V

  Note
t  With the auxiliary heaters supplied by Audi, the auxiliary heater and the operating and display unit, Climatronic control unit -J255- are actuated in auxiliary heating and auxiliary ventilation mode by way of the convenience data bus system. If the operating and display unit, Climatronic control unit -J255- is actuated by way of the input (at connector “D”, contact “10”), the various functions are only available to a limited extent.
t  If, after switching off the ignition, the operating and display unit, Climatronic control unit -J255- remains in operation and “ON” is displayed, locate and eliminate short to positive to connector “D”, contact “10”.
t  On vehicles with diesel engine and a fuel-driven supplementary heater (vehicles with auxiliary heater and no electrically operated supplementary heater) or with a factory-fitted auxiliary heater, there is no direct actuation link between the auxiliary heater (auxiliary heater control unit -J364-) and the operating and display unit, Climatronic control unit -J255-. The following conditions must be fulfilled for the auxiliary heater control unit -J364- to receive a request from the operating and display unit, Climatronic control unit -J255- (via the convenience data bus system) for operation as supplementary heater:
t  - ECON button of operating and display unit, Climatronic control unit -J255- not pressed
t  - Engine speed in excess of 600 rpm
t  - Coolant temperature received via convenience data bus system less than 70 °C (deactivation at approx. 80 °C)
t  - Specified temperature calculated by operating and display unit, Climatronic control unit -J255- for air flowing out of passenger compartment vents greater than 45 °C (heating mode)
t  For further notes, refer to → Auxiliary heating; Rep. Gr.01
t  On vehicles with diesel engine and electrically operated supplementary heater, the request for activation of the supplementary heater is transmitted from the operating and display unit, Climatronic control unit -J255- via the convenience (and drive) data bus system to the relevant engine control unit. For the conditions which have to be fulfilled for the engine control unit to implement the request and switch on the electric supplementary heater, refer to → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Diesel direct injection and glow plug system; Rep. Gr.01.
   
Display zoneSignificanceExplanatory notes
2Auxiliary heating/auxiliary ventilation activation signal from control unit in dash panel insert -J285-
t  Display = “0000”
–  No auxiliary heating/auxiliary ventilation activation signal from control unit in dash panel insert -J285-
t  Display = “0001”
–  Auxiliary heater activation signal from control unit in dash panel insert -J285-
t  Display = “0010”
–  Auxiliary ventilation activation signal from control unit in dash panel insert -J285-
t  Display = “0100”
–  Auxiliary heating/auxiliary ventilation activation signal from control unit in dash panel insert -J285- (e.g. at a pre-set activation time by way of “Timer” function or via auxiliary heater remote control)
–  On the basis of the measued temperatures and the last setting at the operating and display unit, Climatronic control unit -J255-, the operating and display unit, Climatronic control unit -J255- determines whether the auxiliary heater is switched on or whether the operating and display unit, Climatronic control unit -J255- switches to “Auxiliary ventilation mode” and does not issue a request for auxiliary heater activation.
l  Data are transmitted by way of the convenience data bus system

  Note
t  Auxiliary heating/auxiliary ventilation can either be activated and deactivated directly by the driver via the control unit in dash panel insert -J285- or activated and deactivated by the control unit in dash panel insert -J285- at a time and for a period pre-set by the driver in the control unit in dash panel insert -J285-. The control unit in dash panel insert -J285- merely receives the activation or deactivation request via the remote control (from the auxiliary heater control unit -J364-). It relays this request to the operating and display unit, Climatronic control unit -J255-, which determines whether auxiliary heating or auxiliary ventilation is activated. → Auxiliary heating; Rep. Gr.01, → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01
t  The auxiliary heater is also actuated by way of the convenience data bus system. Whether or not the activation request is contained in the data telegram of the operating and display unit, Climatronic control unit -J255- is however not displayed in the measured value block of the operating and display unit, Climatronic control unit -J255-. This data telegram is evaluated by the auxiliary heater control unit -J364- and the control unit in dash panel insert -J285- and the presence of the activation signal is displayed in the measured value block. → Auxiliary heating; Rep. Gr.01, → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01
   
Display zoneSignificanceExplanatory notes
3Request for activation of fresh air blower from auxiliary heater to operating and display unit, Climatronic control unit -J255-
t  Display = “Off”
–  No auxiliary heater request
t  Display = “On”
–  Auxiliary heater request made
l  Data are transmitted by way of the convenience data bus system
4Maximum, still permissible auxiliary heater ON time in seconds calculated by operating and display unit, Climatronic control unit -J255-
t  Display = “0 .... 3770 s”
l  Data are transmitted by way of the convenience data bus system

  Note
t  For the conditions which must be fulfilled for the auxiliary heater control unit -J364- to transmit a request for fresh air blower activation, refer to → Auxiliary heating; Rep. Gr.01
t  The maximum permissible auxiliary heater ON time is 1 hour (3600 s). The actual ON time set in the control unit in dash panel insert -J285- may however be shorter. → Auxiliary heating; Rep. Gr.01, → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01
t  To ensure deactivation of the auxiliary heater after max. one hour even if there is a fault in the control unit in dash panel insert -J285-, the operating and display unit, Climatronic control unit -J255- starts counting down from approx. 3770 s (1 hour plus roughly 3 min. tolerance) as soon as an activation signal is applied. Once the time has elapsed, the auxiliary heater is deactivated by the operating and display unit, Climatronic control unit -J255- even if there is still an activation signal from the dash panel insert → Auxiliary heating; Rep. Gr.01, → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr. 01.
   

Display groups "023” to "025” > < Display group "021”