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Display group "002” > < Display groups "001” to "005”

A4 Cabriolet Mk2

Display group “001”
Display group “001”
Current operating voltage, current voltage at auxiliary heater control unit -J364-, undervoltage shutoff value and type of undervoltage shutoff
   
Display zoneDisplay
1Current battery -A- voltage (in V)
t  If display value is lower than specified battery voltage with auxiliary heater and ignition switched off:
–  Check battery -A- (charge and condition).
–  Check for open circuit or contact resistance in wiring between battery -A- and auxiliary heater control unit -J364- (positive and earth connections to contacts “4” and “9” in vehicle connector at auxiliary heater control unit -J364-). → Chapter
t  If display value is less than specified voltage for alternator -C- with auxiliary heater switched on and engine running:
–  Check battery -A- and alternator -C-. → Electrical system; Rep. Gr. 01 and → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.

  Note
t  If the voltage between contacts “5” and “10” in the vehicle connector at the auxiliary heater control unit -J364- is considerably less than that between contacts “9” and “4”, the power of the auxiliary heater is reduced by the auxiliary heater control unit -J364-.
t  Slight differences between the voltage values displayed in zones “1” and “2” are normal (conversion factor, different wiring connections).
t  At present, the maximum battery voltage displayed in zone “1” is approx. 13.5 V.
   
Display zoneDisplay
2Current voltage at auxiliary heater control unit -J364- (in V)
t  If display value is lower than specified battery voltage with auxiliary heater and ignition switched off:
–  Check battery -A- (charge and condition).
–  Check for open circuit or contact resistance in wiring between battery -A- and auxiliary heater control unit -J364- (positive and earth connections to contacts “5” and “10” in vehicle connector at auxiliary heater control unit -J364-) → Chapter.
t  If display value is lower than specified battery voltage with auxiliary heater switchd on and ignition switched off:
–  Check battery -A- (charge and condition) and alternator.
–  Check for contact resistance in wiring between battery -A- and auxiliary heater control unit -J364- (positive and earth connections to contacts “5” and “10” in vehicle connector at auxiliary heater control unit -J364-) → Chapter.

  Note
t  If the voltage between contacts “5” and “10” in the vehicle connector at the auxiliary heater control unit -J364- is considerably less than that between contacts “9” and “4”, the power of the auxiliary heater is reduced by the auxiliary heater control unit -J364-.
t  Slight differences between the voltage values displayed in zones “1” and “2” are normal (conversion factor, different wiring connections).
   
Display zoneDisplay
3Voltage value for undervoltage shutoff (in V)
l  Code “00XX1”
–  With display in zone “4” (Automatic): Greater than 11.00 V and less than 12.3 V (depending on applicable current temperature and battery voltage entered in adaption function)
–  With display in zone “4” (Manual): Voltage entered in “Adaption” function for “supplementary heating” mode of auxiliary heater, greater than or equal to 9.50 V and less than 10.50 V
l  Code “00XX2”
–  With display in zone “4” (Manual): Voltage entered in “Adaption” function greater than 11.30 V
4Type of undervoltage shutoff
l  Display = Automatic
–  Code “00XX1” entered
–  Factory code
l  Display = Manual
–  Code “00XX2” entered
–  Code “00XX1” entered and auxiliary heater last used as supplementary heater

  Note
t  A voltage of 12.17 V is currently set at the factory for undervoltage shutoff. This setting is active with code “00XX1” and can be altered by way of the “Adaption” function → Chapter.
t  Code “00XX2” is intended for an auxiliary heater version as supplementary heater to be introduced at a later date (with no circulation pump -V55-) and is not to be used for vehicles with auxiliary heater.
t  Depending on the version of the auxiliary heater control unit -J364- and the last active setting “Auxiliary heater” or “Supplementary heater”, the type of undervoltage shutoff active in this setting is displayed with code “00XX1”. The corresponding voltage value can be seen in display zone “3”.
t  As code “00XX2” is only intended for vehicles with supplementary heater with no auxiliary heater, a voltage of 9.5 V is set at the factory. However, in view of the fact that the supplementary heater is only switched on when the engine is running, the shutoff voltage is of secondary importance with regard to supplementary heating.
t  If the code “00XX2” is entered during service work for vehicles with auxiliary heater, the shutoff voltage envisaged by the manufacturer for this code must be set by way of the “Adaption” function to 11.30 V or above so as not to jeopardise reliable starting of the engine.
t  On starting, the shutoff voltage displayed in zone “3” is not active with code “00XX1”. The auxiliary heater is only switched off in the starting phase if the voltage is less than 9.5 V.
t  If the voltage value displayed is not reached for a specific period, undervoltage shutoff is implemented → Chapter.
   
SignificanceCode “00XX1”Code “00XX1”Code “00XX2”
–  Temperature of coolant in auxiliary heater on starting
+ 20 °C- 20 °CAny
Output voltage entered in “Adaption” function for battery -A- at + 20 °C or above12.17 V12.17 V11.30 V
–  Value stored in auxiliary heater control unit -J364- for battery -A- voltage dip during operation of auxiliary heater (temperature-sensitive voltage correction value)
( - ) 0.51 V( - ) 0.88 V-
Battery -A- voltage at which undervoltage shutoff takes place (displayed in measured value block, display group 003)11.66 V11.29 V11.30 V

  Note
t  The shutoff voltage entered in the “Adaption” function, the actual shutoff voltage calculated (by the auxiliary heater control unit -J364-) and the voltage determined at the battery -A- are displayed in the measured value block, display group “001”.
t  The output voltage entered in the “Adaption” function for the battery -A- at + 20 °C can be read out by way of adaption function “10” → Chapter.
t  Batteries tend to supply less energy at low temperatures, however more power is required to start a cold engine. With code “00XX1”, the temperature-sensitive undervoltage shutoff ensures that the auxiliary heater remains operative over a wide range under the various usage conditions without impairing engine starting performance.
   

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