Audi A3 1997 - Page 50

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34 display zone 1 and Workshop Manual, Current flow Diagrams, Electrical Fault finding and Fitting Loca‐
tions binder).
=> Current Flow Diagrams, Electrical Fault-Finding and Fitting Locations
Display zone Display
3
AC pressure switch -F129 (for vehicles without High-pressure sensor -G65).
1 = Open pressure switch (voltage at connector -C- contact -2- less than 2 V).
0 = Closed pressure switch (circuit pressure OK, voltage at connector -C- contact -2- greater
than 2 V).
Positive signal from -J293 (for vehicles with high-pressure sensor -G65).
1 = Positive signal not present (pressure in circuit not OK)
- Voltage at connector -C-, contact -2- lower than 2 V (with one -E87 with two displays)
- Voltage at connector -D-, contact -7- lower than 2 V (with one -E87 with one display)
0 = Positive signal present (pressure in circuit OK)
- Voltage at connector -C-, contact -2- higher than 2 V (with one -E87 with two displays)
- Voltage at connector -D-, contact -7- higher than 2 V (with one -E87 with one display)
Notes on display zone 3:
◆ Radiator fan control unit -J293 versions and vehicle wiring differ for vehicles with pressure switch -F129 and
high-pressure sensor -G65.
=> Parts List
=> Current Flow Diagrams, Electrical Fault-Finding and Fitting Locations
◆ When air conditioner pressure switch -F129 is open (high/low pressure switch between contacts 1 and 2),
the compressor is switched off (=>display group 001, Page 34 display zone 1).
◆ If the refrigerant circuit pressure is less than 1.4 bar (overpressure) or less than 31 bar (vacuum), control
unit -J293 relays no positive signal (for vehicles with high-pressure sensor -G65) to -E87 and the compressor
is switched off.
Display zone Meaning Explanatory Notes
4 Operating and display unit -E87 with two displays
▪ Display zone not used.
Ignore display
Operating and display unit -E87 with one display
▪ Actuation of rear window heating
Display 0 = Heated rear window off ▪ Voltage at connector F, contact 1 (output
from -E87 to the heated rear window) less
than 5 V
Display 1 = Heated rear window on ▪ Voltage at connector F, contact 1 (output
from -E87 to the heated rear window) greater
than 5 V
Notes (for display zone 4 with an -E87 with one display):
◆ Check the actuation of the heated rear window =>Page 87 .
◆ If the ambient temperature is below 0 °C, the rear window heating remains activated until ignition is switched
off (can be deactivated manually at any time). If, during the journey, the temperature rises above 0°C, the
rear window heating is deactivated after the operating period stored in -E87 (approx. 10 minutes) has
elapsed.
◆ If the ambient temperature is above 0 °C, the rear window heating is automatically deactivated by -E87 after
the operating period stored within it (approx. 10 minutes) has elapsed.
Audi A3 1997 ➤
Heating, Air Conditioner - Edition 06.2000
44 01 - Self-diagnosis, Electrical check