audi Workshop Repair Guides

Audi Workshop Service and Repair Manuals

ABOUT US
Checking of front seat heating and ventilation > < Checking of electrical components actuated by the air conditioner

A4 Mk3

Checking of heated rear windowZ1
Checking of heated rear window -Z1-
  Note
t  If switch-on of the heated rear window is not permissible for some reason (short circuit in connection to heated rear window relay -J9-, open circuit in power supply to convenience system central control unit -J393- etc.), this is stored as a fault in the convenience system central control unit -J393- and the air conditioner operating and display unit, Climatronic control unit -J255- is informed by way of the data bus that the event recorder in the convenience system central control unit -J393- must be read out → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051. Actuation of the heated rear window -Z1- is displayed in the measured value block of the convenience system central control unit -J393- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
t  If the voltage at the onboard supply control unit -J519- or the voltage measured at terminal „30“ drops below a value stored in the onboard supply control unit -J519- or the air conditioner operating and display unit, Climatronic control unit -J255-, the heated rear window is completely deactivated (or the power reduced), thus relieving the load on the alternator -C- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
t  If the heated rear window has to be shut off on account of undervoltage, the indicator lamp in the heated rear window button in the air conditioner operating and display unit, Climatronic control unit -J255- remains lit. If however shut-off lasts longer than approx. 150 s, the air conditioner operating and display unit, Climatronic control unit -J255- switches off the indicator lamp.
t  The measured value block of the air conditioner operating and display unit, Climatronic control unit -J255- shows that the heated rear window is being actuated or indicates why there is no actuation in spite of a corresponding request → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
t  Checking of heated rear window actuation is described in the guided fault-finding for the convenience system central control unit -J393- → "Guided fault-finding" function of vehicle diagnostic, testing and information system.
t  At ambient temperatures below 0 °C, the heated rear window remains switched on until the ignition is switched off (manual deactivation is possible at any time). If the temperature during a driving cycle rises above 0 °C, the heated rear window is deactivated on completion of the operating period stored in the air conditioner operating and display unit, Climatronic control unit -J255- (approx. 10 minutes) → Owner's manual.
t  At ambient temperatures above 0 °C, the heated rear window can be deactivated automatically on completion of the operating period stored in the air conditioner operating and display unit, Climatronic control unit -J255- (approx. 10 minutes) by the air conditioner operating and display unit (the actuation time is governed by the encoding and version of the air conditioner operating and display unit, Climatronic control unit -J255-) → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
t  As of Model Year 2010 a start/stop system will be available as an optional extra for this vehicle in conjunction with certain engines. On vehicles with a start/stop system, the heated rear window is deactivated whilst the stop function is active (to protect the battery -A-). The setting for actuation of the heated rear window -Z1- does however remain stored in the operating and display unit, Climatronic control unit -J255-. Once the engine has been re-started via the start function, the heated rear window is actuated again → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
   

Checking of front seat heating and ventilation > < Checking of electrical components actuated by the air conditioner