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Display group "019” > < Display group "017”

A4 Mk2

Display group “018”
Display group “018”
Time period transmitted by control unit in dash panel insert -J285- for “Ignition off” and ignition key assignment transmitted, windscreen wiper signal transmitted by steering column electronics control unit -J527- and operating status transmitted by fresh air blower control unit -J126- for fresh air blower -V2-
   
Display zoneSignificanceExplanatory notes
1Time transmitted by control unit in dash panel insert -J285- for period between ignition being switched off and on
t  Display = “00:00 ... XX:XX h”
–  Ignition off time (standing time) in hours and minutes
l  Data are transmitted by way of the convenience data bus system

  Note
t  If an “ignition off time” signal is not detected by the operating and display unit, Climatronic control unit -J255- when the ignition is switched on, the operating and display unit, Climatronic control unit -J255- assumes a standing time of more than 4 hours and the engine temperature is taken to be the same as the ambient temperature. In heating mode, for example, this may lead to delayed start-up of the fresh-air blower despite the engine being warm. The ambient temperature indicator -G106- in the dash panel insert may also display incorrect ambient temperature values.
t  After a standing time of 4 hours, the operating and display unit, Climatronic control unit -J255- assumes for temperature calculation purposes that all vehicle components are at ambient temperature.
t  Depending on the hardware/software version of the operating and display unit, Climatronic control unit -J255-, the display in this zone is limited to a value stored in the operating and display unit, Climatronic control unit -J255- (e.g. 3:59 h, 04:46 h) or the actual time is displayed.
t  Following connection of the battery -A-, the control unit in dash panel insert -J285- may effect re-start (reset) and may therefore not be able to transmit a time signal when the ignition is first switched on. If applicable, switch off ignition for several minutes and check time period displayed after switching ignition back on.
   
Display zoneSignificanceExplanatory notes
2Ignition key assignment transmitted by control unit in dash panel insert -J285-
t  Display = “0”
–  The ignition was switched on with a key for which there is no assignment in the control unit in dash panel insert -J285-
t  Display = “1 .... 4”
–  The ignition was switched on using the key set in the control unit in dash panel insert -J285- to position 1 (2, 3 or 4).
l  Data are transmitted by way of the convenience data bus system
–  Check adaption of ignition key → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051. and → Electrical system; Rep. Gr.90
–  Up to 4 keys can be assigned.

  Note
t  Ignition key assignment can only be detected and thus transmitted by the control unit in dash panel insert -J285- on vehicles fitted with an immobilizer → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.90 (Servicing dash panel insert).
t  When the ignition is switched on, the operating and display unit, Climatronic control unit -J255- starts with the settings which were valid the last time the ignition was switched off with this key (temperature, air distribution, fresh air blower speed).
t  If the ignition is switched on using a key not released for this vehicle (e.g. by way of the emergency starting function), the operating and display unit, Climatronic control unit -J255- as of hardware/software version “0711” switches automatically to “Off” mode after switching on the ignition and can only be switched to “Def” mode with the ignition switched on (no other settings possible). At the same time, a fault is stored in the operating and display unit, Climatronic control unit -J255- (Immobilizer control unit -J334-). This function was incorporated as part of enhancement of the anti-theft protection system.
   
Display zoneSignificanceExplanatory notes
3Signal for windscreen wiper operating status from steering column electronics control unit -J527-
t  Display = “00000”
–  No windscreen wiper or wipe/wash operation activated (wipers in rest position)
t  Display = “X0001”
–  Intermittent windscreen wiper operation
t  Display = “X0010”
–  Windscreen wiper speed “1” operation
t  Display = “X0100”
–  Windscreen wiper speed “2” operation
t  Display = “X1000”
–  Windscreen wiper wipe/wash mode
t  Display = “10000”
–  Intended for windscreen wiper operation via rain sensor (introduction not yet finalised)
l  Data are transmitted by way of the convenience data bus system
–  The steering column electronics control unit -J527- transmits the information on the current windscreen wiper operating status

  Note
t  Depending on the position of the windscreen wiper switch, several operating statuses may also be displayed simultaneously (e.g. “01001” for wipe/wash mode and intermittent operation).
t  Depending on version, “1XXXX” may be displayed for vehicles without and with rain sensor with the windscreen wipers switched on although it may not be raining (the operating and display unit, Climatronic control unit -J255- assumes that it is raining and sets the display to “1XXXX” even thougth there is no signal from the rain sensor).
t  The operating status information is required to regulate the evaporator outflow temperature and for vehicles with air quality sensor -G238-.
   
Display zoneSignificanceExplanatory notes
4Signal transmitted by fresh air blower control unit -J126- on operating status of fresh air blower in % (duty cycle) 
 
t  Display = 45...54 %
–  Fresh air blower -V2- and fresh air blower control unit -J126- OK
l  No faults present
 
t  Display = “0...10 %”
–  No signal from fresh air blower control unit -J126-
l  Check for short to earth or open circuit in wiring between fresh air blower control unit -J126- and operating and display unit, Climatronic control unit -J255-
l  Open circuit in power supply to fresh air blower control unit -J126-, check
l  Fresh air blower control unit -J126- defective, replace fresh air blower -V2- with fresh air blower control unit -J126-
 
t  Display = “15....24 %”
–  Switching relay (for solar operation) in fresh air blower control unit -J126- defective
l  Replace fresh air blower -V2- with fresh air blower control unit -J126-
 
t  Display = “25...34 %”
–  Voltage at fresh air blower control unit -J126- too high
l  Check power supply to fresh air blower control unit -J126-
 
t  Display = “35...44 %”
–  Voltage at fresh air blower control unit -J126- too low
l  Check and repair power supply and earth connection to fresh air blower control unit -J126-

   
Display zoneSignificanceExplanatory notes
4
t  Display = “55...64 %”
–  Fresh air blower -V2- stiff or blocked
l  Remove fresh air blower -V2- and check for foreign matter
l  Replace fresh air blower -V2- with fresh air blower control unit -J126-
 
t  Display = “65...74 %”
–  Fresh air blower -V2- stiff or blocked
–  Short circuit in fresh air blower control unit -J126- or fresh air blower -V2-
l  Remove fresh air blower -V2- and check for foreign matter
l  Replace fresh air blower -V2- with fresh air blower control unit -J126-
 
t  Display = “75...84 %”
–  No actuation signal from operating and display unit, Climatronic control unit -J255- being applied to fresh air blower control unit -J126- (e.g. air conditioner switched off)
l  Activate actuation of fresh air blower -V2- at operating and display unit, Climatronic control unit -J255-
l  Check for open circuit in wiring between fresh air blower control unit -J126- and operating and display unit, Climatronic control unit -J255-
 
–  Implausible signal from fresh air blower control unit -J126- (signal frequency outside permissible tolerance)
–  Fresh air blower control unit -J126- defective, replace fresh air blower -V2- with fresh air blower control unit -J126-
 
t  Display = “95...100 %”
–  No signal from fresh air blower control unit -J126-
l  Check for short to positive in wiring between fresh air blower control unit -J126- and operating and display unit, Climatronic control unit -J255-
l  Fresh air blower control unit -J126- defective, replace fresh air blower -V2- with fresh air blower control unit -J126-

  Note
t  If actuation of the fresh air blower is OK and the fresh air blower control unit -J126- does not detect any faults, the current fresh air blower speed is transmitted by way of a square-wave signal to the operating and display unit, Climatronic control unit -J255-. With this square-wave signal the duty cycle is approx. 50% and the frequency 1/20 of the fresh air blower speed (example: at a fresh air blower speed of 3000 rpm the frequency of the square-wave signal is 150 Hertz or pulses per second).
t  If a fault is detected by the fresh air blower control unit -J126-, the fresh air blower control unit -J126- transmits a square-wave signal with a frequency of 10 Hertz (pulses per second). The operating and display unit, Climatronic control unit -J255- recognises the fault detected by way of the duty cycle.
   

Display group "019” > < Display group "017”