Audi Workshop Service and Repair Manuals

Notes:

• ◆ To ensure that misted windows are de-misted as soon as possible, air recirculation mode will not operate with "air to windscreen". (Switch -E159 is released mechanically via the rotary control).
• ◆ In air recirculation mode, the windows may become misty (the air humidity inside the vehicle increases and moisture condenses on the windows - the air is not dried as it is in vehicles with air conditioners).
• ◆ Different types of the heater controls:

=> Parts List

• ‒ For vehicles up to and including model year 2000 (only with switch -E159).
• ‒ For vehicles as of model year 2001 (with switch -E159 and with switch for heated rear window).

• ◆ Function of switch for heated rear window =>Page 80-13

Check function of switch -E159 and positioning motor -V154

• ‒ Switch on ignition.
• ‒ → Set rotary switch -A- for fresh air blower -V2 to speed 3.
• ‒ Turn rotary control -B- for air distribution to the "Air to dash panel vents" position.
• ‒ Do not activate switch -C- for fresh/recirculation air flap -E159 (key with arrow; the illustration shows the type which were installed up to and including model year 2000).

• Air is drawn in through the dust and pollen filter (fresh air mode - telltale in switch does not illuminate).

• ‒ Actuate switch -C- (air recirculation mode - telltale in switch illuminates).

• Air is drawn out of the passenger's footwell area (air recirculation mode).

• ‒ → Turn rotary control -B- for air distribution to end stop in the "Air to windscreen" position.

• Telltale in switch -C- extinguishes, fresh/recirculated air flap moves to the "fresh air mode" position (-E159 is released via rotary control -B-).

Notes:

• ◆ If the function is OK, but the windows mist up:
• ‒ Check dust and pollen filter for dirt =>Page 80-35
• ‒ Check forced air extraction =>Page 80-6
• ‒ Check passenger compartment for the ingress of water.
• ◆ If the function is NOK, check switch -E159.

Check function of switch -E159

• ‒ Remove glove compartment.

=> Inner Body Assembly; Repair group 68

• ‒ → Detach connector -A- from positioning motor for fresh/recirculation air flap -V154.
• ‒ Switch ignition on.
• ‒ Turn rotary control for air distribution to the "Air to dash panel vents" position.
• ‒ Switch -E159 is not actuated (not pressed).

• Fresh air mode - telltale does not illuminate in switch.

• ‒ Activate voltage tester V.A.G 1527 between contact 1 and 3 at connector -A- (between contact 2 and 3 in RHD vehicles).

• Telltale in voltage tester illuminates.

• ‒ Actuate switch -E159 (press).

• Air recirculation mode - telltale illuminates in switch.
• Telltale in voltage tester extinguishes.

• ‒ → Activate voltage tester between contacts 2 and 3 on connector -A- (between contacts 1 and 3 for RHD vehicles).

• Telltale in voltage tester illuminates.

• ‒ Turn rotary control for air distribution to end stop in the "Air to windscreen" position.

• Telltale in switch and in voltage tester extinguishes.

Notes:

• ◆ If no faults are determined during this test:
• ‒ Check the freedom of movement of the fresh/recirculated air flap.
• ‒ Replace positioning motor -V154.
• ◆ If the function is NOK:
• ‒ Check the wiring between -E159 and -V154 for open circuit or short circuit.
• ‒ Check the power supply and earth connection to switch -E159.
• ‒ Replace heater control.