Checking solenoid valve 2 for activated charcoal filter -N333 (fuel tank breather valve 2) — AUDI

Fitting locations overview =>
24-5

Testing for leaks

When there is no electrical supply, the fuel tank breather valve 2 -N333 remains closed.

Disconnect hoses from ACF valve but leave the electrical connector plugged in.
Connect auxiliary hose to one connection of ACF valve.

Connect vehicle diagnostic, testing and information system VAS 5051 and select engine control unit 2 using "address word" 11 => Page
01-9
.
For this purpose, the ignition must be switched on.
Start final control diagnosis and actuate fuel tank breather valve 2 -N333 =>Page
01-111
.

Display on VAS 5051:

A -
1st control element in test
1 -
Fuel tank breather valve 2 -N333

The valve should click ...
... and should open and close (check by blowing into the auxiliary hose).

If the injector does not click:

Checking internal resistance to ACF valve.

If valve does not open or close properly:

Replace fuel tank breather valve 2 -N333.

Checking internal resistance

Unplug connector on ACF valve.

Connect multimeter between contacts 1 and 2 on valve to measure resistance.
Specified value: 22 ... 30 ω

If specification is not attained:

Replace solenoid valve 2 for activated charcoal filter -N333.

If specified value is attained:

Check the voltage supply
=>Page
24-206
.

Checking power supply

Test requirements:

Fuse for ACF valve OK.

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

Fuel pump relay OK.

Note:

The ACF valve receives its power supply via the fuel pump relay.

Unplug connector on ACF valve.

Connect voltage tester V.A.G 1527 B as follows:

Connector / Contact · Measure to
1 · Engine earth

Operate the starter briefly (the engine may start).
The LED should illuminate.

If the LED does not illuminate:

Check the wiring from contact 1 on the connector via the fuse to the fuel pump relay for an open circuit:

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

Rectify open circuit, if necessary.

If the LED illuminates:

Check actuation.

Checking actuation

Connect voltage tester V.A.G 1527 B to contacts 1 (positive) and 2 of the connector.
Start final control diagnosis in engine control unit 2 and actuate fuel tank breather valve 2 for activated charcoal filter -N333 =>Page
01-111
.
The LED should flash.

If the LED lamp does not flash or if it illuminates continuously:

Connect test box V.A.G 1598/31 to wiring harness for engine control unit 2; the engine control unit should not be connected =>Page
24-31
.

Check for open circuit and short to positive or earth in the following wiring connection:

Connector / Contact · Test box V.A.G 1598/31 / Socket
2 · 64

Rectify any open/short circuit as necessary.

If the wiring is OK:

Replace engine control unit 2 =>Page
24-38
.