Audi Workshop Service and Repair Manuals

Notes:

• ◆ To ensure misted up windows are demisted as soon as possible, air recirculation mode will not operate with "air to windscreen". (Switch -E159 is released mechanically via the rotary switch).
• ◆ In recirculated air mode the windows may become misty (the air humidity inside the vehicle increases and moisture condenses on the windows and the air is not dried as it is in vehicles with air conditioners).

Special tools, testers and auxiliary equipment required

• ◆ Voltage tester V.A.G 1527 B

Checking the function of the positioning motor for the fresh-air/recirculated-air flap

• ‒ Switch the ignition on.
• ‒ → Set the switch -A- for the fresh-air blower -V2 to speed 3.
• ‒ Turn the air distribution control -B- to the "dash panel vents".

• ‒ → Do not actuate switch -C- for fresh-air/recirculated-air flap -E159 (fresh air mode, telltale in the switch does not light).
• ‒ The air is drawn in via the dust and pollen filter
• ‒ Actuate switch -C- (air recirculation mode, telltale in switch lights).
• ‒ The air is drawn out of the passenger's footwell area.
• ‒ Turn the air distribution control -B- to the "windscreen" stop.
• ‒ Telltale in switch -C- goes out, fresh-air/recirculated-air flap goes into the position "fresh air mode" (-E159 is released via rotary switch -B-)

Notes:

• ◆ If the function is OK, but the windows mist up:
• ‒ Check dust and pollen filter for contamination .
• ‒ Check forced air extraction =>Page80-8.
• ‒ Check passenger compartment for the ingress of water.
• ◆ If the system is not OK, test switch -E159.

Check the function of the switch for the fresh-air/recirculated-air flap -E159

• ‒ Remove the glove box

=> General Body Assembly, Interior; Repair group 68; Storage compartments/covers; Removing and installing glove box

• ‒ → Detach connector -A-.
• ‒ Switch the ignition on.
• ‒ Turn air distribution control to "dash panel vents".
• ‒ Do not actuate switch for fresh-air/recirculated-air flap -E159 (the telltale in the switch does not light).

• ‒ → Connect the voltage tester V.A.G 1527 B between contacts 1 and 3 in connector -A- (contacts 2 and 3 in right-hand drive vehicles).
• ‒ The LED should light up.
• ‒ Actuate switch for fresh-air/recirculated-air flap -E159 (the telltale in the switch lights).
• ‒ Test lamp should not light up

• ‒ → Connect the voltage tester V.A.G 1527 B between contacts 1 and 3 in connector -A- (contacts 2 and 3 in right-hand drive vehicles).
• ‒ The LED should light up.
• ‒ Turn the air distribution switch to the "windscreen" stop.
• ‒ The LED must not light, the telltale in the switch goes out.

Notes:

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

=> Current Flow Diagrams, Electrical Fault-finding and Fitting Locations binder

• ‒ Check the power supply and earth connection to switch -E159.
• ‒ Replace the heater control .