Intake air changeover valve -N335 — AUDI

AQJ ASG ANK
In all S6 models a flap is switched in the air filter via the intake air changeover valve -N335.

Only perform test when there is a lack in performance or a fault was registered.

The changeover on a shorter intake path in the air filter is dependent on speed and load.

Fitting location of intake air changeover valve -N335 see => Page
24-165
.

Note:

At the front of the air filter bottom housing there is a round opening. When reaching inside with one finger a flap can be felt.

Checking function

Start the engine.
Accelerate sharply, the flap in the bottom part of the air filter must open at the same time.

If the flap does not open when accelerating sharply:

Check intake air changeover valve -N335.
Check vacuum system for leaks => Page
24-162
.

Checking intake air changeover valve -N335

Switch the ignition on.
Perform final control diagnosis and actuate valve for intake air changeover -N335 =>Page
01-74
.

Final control diagnosis
⇒
Intake air changeover valve
-N335
Indicated on display:

The valve should click (clicking can be heard and felt). After 1 minute the final control diagnosis is terminated.

If the solenoid valve does not click:
Switch ignition off.
Unplug connector from intake air changeover valve -N335.

Measure resistance between contacts on solenoid valve using the hand-held multimeter V.A.G 1526.

Specified value: 25...35 Ohms

If the specified value is not attained, renew intake air changeover valve -N335.

If the specified value is achieved, check the voltage supply.

Checking power supply to intake air changeover valve -N335

Connect diode test lamp V.A.G 1527 between engine earth and socket 1 (positive) on connector using cables from adapter set V.A.G 1594.
Operate starter briefly.

The diode test lamp should illuminate.

If the diode test lamp does not illuminate:
Check the fuse for the intake air changeover valve -N335.

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

If the fuse is OK:

Check for open circuit and short in wiring between fuel pump relay and socket 1 on connector via fuse for intake air changeover valve -N335.

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

If the voltage supply is okay check the actuation of intake air changeover valve -N335.

Re-insert the fuel pump relay and fuse.

Checking actuation of intake air changeover valve -N335

Connect diode test lamp V.A.G 1527 between sockets 1 and 2 on connector for intake air changeover valve -N335 using cables from adapter set V.A.G 1594.
Perform final control diagnosis and actuate valve for intake air changeover -N335 =>Page
01-74
.

Final control diagnosis
⇒
Intake air changeover valve -N335
Indicated on display:

If the diode test lamp does not flash or is continuously lit: Check the wiring.

Checking wiring

Connect test box V.A.G 1598/31 to wiring harness for engine control unit; do not connect the engine control unit => Page
24-12
.

Check the following wiring connections for open circuit and short circuit to positive or earth.

Unplug connector from intake air changeover valve -N335 / Socket · Test box V.A.G 1598/31 socket
2 · 45

Wire resistance: max. 1.5 Ohm

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

If the wiring is OK replace engine control unit =>Page 24-13.
Check intake manifold changeover valve again for function =>Page
24-157
.