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The final control diagnosis is complete.
Notes:
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◆ Final control diagnosis can be terminated by pressing the C key.
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◆ Interrogating fault memory on completion of final control diagnosis => Page 01-15.
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◆ On the termination of the final control diagnosis, interrogate the fault memory => Page 01-110.
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◆ The actuation of the temperature sensor blower -V42 is performed on an operating and display unit
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‒ with one display after the actuation of the radiator fan.
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‒ with two displays after the actuation of the air-flow flap positioning motor.
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◆ The actuation of the outside air temperature display -G106 is performed on an operating and display unit
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‒ with one display after the actuation of the air-flow flap positioning motor.
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‒ with two displays after the actuation of the idle control.
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◆ On operating and display units with one display, after the actuation of the last component, the end of the final control diagnosis is indicated (display on the fault reader "END").
Final controls actuated
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Indicated on display
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Desired function
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Fault remedy
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Air conditioner magnetic clutch -N25
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- The magnetic clutch is engaged and disengaged in a 3-second cycle -, the compressor is driven with the magnetic clutch engaged
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- Use the current flow diagram to check the power supply for the magnetic clutch -N25 (via relay -J44)
Repair magnetic clutch -N25 => Page 87-35
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▪ The output "Compressor intervention" connector C, contact 12 is actuated at the same time 1)
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The output from the operating and display unit-E87 is switched in a 2-second cycle from 0 V to 12 V; checking => Page 01-60
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- Use the current flow diagram to check the cabling between -E87, -J44 and -N25
Replace operating and display unit -E87 => Page 87-63
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1) Only check the output "Compressor intervention", if complaints have been received.
Notes:
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◆ The engine control unit uses the signal "air conditioner intervention" to compensate the brief additional engine loading when the compressor is switched on. The compressor may also be switched off by the motor control unit via this output (input) =>Reading measured value block, display group 001, Page 01-110 or:
=> Relevant Workshop Manual for Injection and Ignition System; Repair group 24
=> Relevant Workshop Manual for Diesel Direct Injection and Glow Plug System; Repair group 23
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◆ Check the output, for example by switching the compressor on and off using the "Frost symbol" button or ECON button, while the control unit's measured value block is read with the engine running:
=> Relevant Workshop Manual for Injection and Ignition system; Repair group 24
=> Relevant Workshop Manual for Diesel Direct Injection and Glow Plug System; Repair group 23
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Indicated on display
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Desired function
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Fault remedy
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Fresh-air blower -V2
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- Fresh-air blower -V2 running
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- Check the freedom of movement of the fresh-air blower
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▪ Fresh-air blower voltage for 2 seconds in each case:
▪ 0 V, 3 V, 6 V, 9 V, 12 V, 15 V,
▪ 0 V etc.
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- Use the current flow diagram to check the earth connection for the fresh-air blower control unit -J126
Check fresh-air blower control unit -J126 => Page 87-63
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DANGER: Fan is switched on
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Info display
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WARNING:
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After the next actuation of the ⇒key, the radiator fan -V7 is switched on. Do not reach into the fan area.
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Indicated on display
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Desired function
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Fault remedy
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Radiator fan -V7
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- The radiator fan -V7 is switched on and off in a 5-second-cycle.
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- Use the current flow diagram to check the wiring between the operating and display unit -E87 and the radiator fan relay -J26 for open circuit or short to positive
Check the actuation of the radiator fan -V7 from the radiator fan relay -J26:
=> "Current Flow Diagrams, Electrical Fault-finding and Fitting Locations" binder
Check the function of the radiator fan relay -J26 => Page 87-63
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Note:
The radiator fan -V7 is switched to the 2nd speed by the radiator fan 2nd speed relay -J101:
- when radiator fan thermoswitch-F54 is closed
- when air conditioner high-pressure switch -F23 / air conditioner pressure switch -F129 is closed (switch section for radiator fan).
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Indicated on display
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Desired function
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Fault remedy
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Two-way valve for fresh-air and recirculated-air flap -N63
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- Fresh-air and recirculated-air flap switches in a 5-second cycle between fresh air - and air recirculation mode.
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- Check vacuum supply via the two-way valve -N63 => Page 87-76
Replace two-way valve -N63
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Notes:
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◆ The "two-way valve for the fresh-air and recirculated-air flap -N63" is only present in vehicles up to Model Year 1996 and is addressed in the final control diagnosis.
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◆ Vehicles from Model Year 1997 are not fitted with the "two-way valve for the fresh-air and recirculated-air flap -N63" (the fresh-air and recirculated-air flap is operated by the positioning motor -V71).
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Indicated on display
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Desired function
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Fault remedy
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Temperature flap positioning motor -V68
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- Positioning motor -V68 moves from stop to stop
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- Check the freedom of movement of the temperature flap
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- With -E87 with Part No. 8D0 820 043 up to index "C": Wait until the temperature flap is at the "Heating" stop, then press the ⇒key
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▪ Fresh air blower is running
▪ Air temperature from the vents changes
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- Use current flow diagram to check the wiring between the temperature flap positioning motor -V68 and the operating and display unit -E87 for open circuit or interchange
Check temperature flap positioning motor -V68 => Page 87-63
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Indicated on display
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Desired function
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Fault remedy
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Central flap positioning motor -V70
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- Positioning motor -V70 moves from stop to stop
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- Check the freedom of movement of the central flap
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- With -E87 with Part No. 8D0 820 043 up to index "C": Wait until the central flap is at the stop "Air to footwell/defroster flap", then press ⇒key
Close all dash panel vents
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▪ Fresh air blower is running
▪ Air distribution changes from footwell/defroster to dash panel vents
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- Use current flow diagram to check wiring between positioning motor -V70 and the control and display -E87 for open circuit or interchange
Check air-flow flap positioning motor -V70 => Page 87-63
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Positioning motor for footwell/ defroster flap -V85
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- Positioning motor -V85 moves from stop to stop
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- Check freedom of movement of footwell/defroster flap
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- With -E87 with Part No. 8D0 820 043 up to index "C": Wait until the footwell/defroster flap is at the stop "Air to windscreen", then press ⇒key
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▪ Fresh air blower is running
▪ Air distribution changes from footwell to defrost
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- Use current flow diagram to check wiring between positioning motor -V85 and the control and display -E87 for open circuit or interchange
Check footwell/defroster flap positioning motor -V85 => Page 87-63
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Indicated on display
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Desired function
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Fault remedy
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Air-flow flap positioning motor -V71
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- Positioning motor -V71 moves from stop to stop
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- Check freedom of movement of air-flow flap or fresh-air and recirculated-air flap
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▪ Fresh air blower is running
▪ Air throughput changes (air-flow flap)
Additionally, on vehicles from Model Year 1997:
▪ Air conditioner changes between fresh-air and air recirculation mode (fresh-air and recirculated-air flap)
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- Use current flow diagram to check the wiring between the positioning motor -V71 and the operating and display unit -E87 for open circuit or interchange
Check air flow flap positioning motor -V71 => Page 87-63
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Notes:
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◆ Up to Model Year 1996, the installation of the positioning motor -V71 was dependent upon equipment and it is therefore not installed in all vehicles (e.g. not in right-hand drive vehicles).
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◆ In vehicles from Model Year 1997, in addition to the air-flow flap, the positioning motor also controls the fresh-air and recirculated-air flap. In right-hand drive vehicles, the positioning motor only controls the fresh-air and recirculated-air flap. There is no air-flow flap.
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Indicated on display
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Desired function
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Fault remedy
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Temperature sensor blower -V42 2)
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- Temperature sensor blower -V42 in the dash panel is switched on and off in a 5-second cycle - (smoke is drawn in by blower)
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- Use the current flow diagram to check the wiring between the blower -V42 and operating and display unit -E87 for open circuit or short to earth
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- Test operation of blower -V42, for example using smoke test (hold smoke source in front of the intake frame in the centre part of the dash panel)
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- Use current flow diagram to check power supply for blower -V42
Check intake frame and intake hose for blockage => Page 87-63
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Segment test
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- All segments of the operating and display unit -E87 are switched on and off in a 3-second cycle
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- Replace the bulbs in the operating and display unit -E87=> Page 87-63
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2) The temperature sensor blower -V42 is installed in the operating and display unit -E87 with only one display.
3) In vehicles from Model Year 1997, LEDs are installed instead of bulbs and these cannot be replaced individually.
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Indicated on display
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Desired function
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Fault remedy
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Idle control 4)
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- The output from the operating and display unit -E87 is switched in a 5-second cycle from 0 V to 12 V; checking => Page 01-60
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External temperature display -G106
(in driver information
system)
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- Ambient temperature display -G106 (in the driver information system) is incremented from 40 °C or °F (approx. 3 seconds per increment) 5)
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- Use current flow diagram to check wiring and connectors between the driver information system and the operating and display unit -E87 for open circuit or short circuit
Use current flow diagram to check positive and earth connection for ambient temperature display -G106 for open circuit
Check driver information system
=> Electrical System; Repair group 01; Dash panel insert self-diagnosis87-63
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End
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Info display (only in operating and display units with one display)
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4) Depending upon the vehicle equipment, when the rear window heating is switched on, a positive signal is applied to this output (switch off heated rear window for the test).
=> Current Flow Diagrams, Electrical Fault-finding and Fitting Locations binder
5) In vehicles with an automatic gearbox and driver information system, the external temperature is only displayed with gear engaged
=> Owner's manual
Starting the "idling speed control" final control diagnosis.
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‒ Switch ignition off.
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‒ Remove the engine control unit and connect the appropriate test box to the connector to the engine control unit (the engine control unit is not connected to the test box):
=> Relevant Workshop Manual for Injection and Ignition System; Repair group 24;
=> Relevant Workshop Manual for Diesel Direct Injection and Glow Plug System; Repair group 23
Note:
Pin assignment on connector to engine control unit
=> Current Flow Diagrams, Electrical Fault-finding and Fitting Locations binder
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‒ Connect the fault reader V.A.G 1551 (V.A.G 1552) and use "Address word" 08 to select the air conditioner/heating electronics.
(Connecting fault reader => Page 01-9.)
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‒ Press the PRINT key to switch on the printer - (indicator lamp in key lights up).
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‒ Switch the ignition on.
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‒ Switch off rear window heating.
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