Head Area Heater, Checking: Procedure

Courtesy of AUDI OF AMERICA, LLC

The head area heater is adjusted via the buttons -1 and 2- on the Climatronic Control Module -J255- -item A-.

• When the head area heater is switched on, the function indicator lamps in the buttons -1 and 2- illuminate. Refer to the Vehicle Owner's Manual.
• If it is not possible to switch on the hear area heater due to a switch off condition detected by the Vehicle Electrical System Control Module -J519-, the Vehicle Electrical System Control Module -J519- sends the corresponding information back to the control head via the Data Bus. The function indicator lamps in the buttons -1 and 2- do not illuminate or go out.
• With the ignition switched on and the engine off the head area heater cannot be switched on then the Vehicle Electrical System Control Module -J519- has calculated that the Battery -A- is insufficiently charged. If the Vehicle Electrical System Control Module -J519- has calculated that the head area heater cannot be started due to insufficiently charged Battery -A- depending on the version of the Vehicle Electrical System Control Module -J519- the function indicator lamps in the buttons -1 and 2- can nevertheless stay switched on using the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function for the Vehicle Electrical System Control Module -J519-.
• The levels of the head area heater are adjusted via the Climatronic Control Module -J255-. The set levels for the left and right head area heater is transmitted via the Vehicle Electrical System Control Module -J519- to the Left Head Area Heater Control Module -J846- and the Right Head Area Heater Control Module -J847-. The specified temperature and the target speed for the Left Head Area Heater Fan -V450- and the Right Head Area Heater Fan -V451- in the different head area heater steps are stored in the Left Head Area Heater Control Module -J846- and in the Right Head Area Heater Control Module -J847-. Depending on the Left Head Area Heater Control Module -J846- and the Right Head Area Heater Control Module -J847- version, the specified temperature for the heat area heater can therefore be different for the same setting on the control head Climatronic Control Module -J255- using the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function and refer to the appropriate Wiring Diagram(s).
• The adjusted setting for the head area heater can be stored in a key-dependent manner Climatronic Control Module -J255-. The settings made prior to the ignition being switched off can be applied during the next driving cycle. Refer to the Owner's Manual.
• For vehicles with the Start/Stop System, the head area heater can be switched off to protect the Battery -A- when the stop function is active. The setting for head area heater activation remains stored however in the Climatronic Control Module -J255-. The head area heater is switched on again as soon as the engine is restarted via the start function using the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function (for the Vehicle Electrical System Control Module -J519-).
• For vehicles without the passenger occupant detection system for the front passenger seat, the head area heater is currently not shut-off automatically by the Climatronic Control Module -J255- if a seat is unoccupied while driving. If the ignition is turned off and not turned on again within about 10 minutes, the setting for the head area heater and seat heating activation can be is erased. Refer to the Owner's Manual.
• If, for example, the Vehicle Electrical System Control Module -J519- voltage measured at terminal "30" falls below a value stored in the Vehicle Electrical System Control Module -J519-, the head area heater is output is reduced or switched off completely to reduce the load on the Generator -C- using the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function for the Vehicle Electrical System Control Module -J519-.
• If there is a condition that prevents the driver or passenger head area heating from switching on (for example, there is an open circuit in the voltage supply to the particular control module, etc.), this will be stored as a fault in the Vehicle Electrical System Control Module -J519-. In this vehicle, information stating that the event memory in the relevant control module needs to be checked may not be sent via the Data Bus to the Climatronic Control Module -J255- using the Vehicle Diagnostic Tester in the"Guided Fault Finding"  Function. In the event of a complaint regarding head area heater, first check the event memory of the control modules activating the head area heater and the seat heating, for example the Vehicle Electrical System Control Module -J519-.
• Depending on the version and equipment level of the vehicle, different information for the activation of the head area heater and the seat heating is displayed based on the settings transmitted by the Climatronic Control Module -J255-. Varies in the different measured value blocks in the different control modules using the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function.
• In the "read measured values" function of the"Guided Fault Finding"  , the Climatronic Control Module -J255- control head displays which head area heater level setting has been selected. Depending on the version and the equipment of the vehicle, the activation of the head area heater, the actual and target temperature as well as the target and actual speed for the blower Left Head Area Heater Fan -V450- and Right Head Area Heater Fan -V451-, the actual current flowing over the Left Head Area Heater Control Module -J846- and the Right Head Area Heater Control Module -J847- etc., is displayed in the "read measured values" function for the Vehicle Electrical System Control Module -J519- using the Vehicle Diagnostic Tester in the"Guided Fault Finding"  function.
• The function test of head area heater activation is described in the"Guided Fault Finding"  for the Vehicle Electrical System Control Module -J519- using the Vehicle Diagnostic Tester.