Testing solenoid valve 1 for activated charcoal filter -N80 — AUDI

APR
Note:

In this context, solenoid valve 1 for activated charcoal filter (ACF valve) is also known as the fuel tank breather valve.

Testing for leaks

When there is no electrical signal the solenoid valve remains closed.

Disconnect hoses from solenoid valve 1 for activated charcoal filter -N80.
Connect an auxiliary hose to one of the connections on the ACF valve.
Connect vehicle diagnostic, testing and information system VAS 5051 (or fault reader V.A.G 1551) and select engine electronics control unit by entering address word "01" ( => Page
01-3
.)
When doing this the ignition must be switched on.
Start final control diagnosis and select solenoid valve for activated charcoal filter -N80 (tank breather valve)
=>Page
01-39
.

Final control diagnosis
⇒
ACF solenoid 1 -N80
Indicated on display:

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

If the valve does not click, carry out electrical test of solenoid valve 1 for activated charcoal filter => Page
24-110
.
If valve does not open and close properly, renew solenoid valve 1 for activated charcoal filter.

Electrical test of solenoid valve 1 for activated charcoal filter -N80

Unplug connector from ACF valve -N80.
Measure resistance between contacts on valve using hand-held multimeter V.A.G 1526.

Specification: 22...30 ω

If the specification is not attained:

Renew solenoid valve for activated charcoal filter system -N80.

If the specification is attained:

Test voltage supply => Page
24-111
.

Testing power supply to solenoid valve

Note:

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

Test fuse for ACF valve

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

If the fuse is OK:

Unplug connector on ACF valve -N80.
Connect diode test lamp V.A.G 1527 between engine earth and socket 1 on the connector.
Operate starter.

The diode test lamp should light up.

If diode test lamp does not light up:

Test continuity of wiring from socket 1 to fuel pump relay via fuse. Rectify open circuit if necessary.

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

If wiring is OK, test fuel pump relay
=> Page
24-41
.

If the diode test lamp lights up, test activation
=> Page
24-112
.

Testing activation of ACF solenoid valve

Connect diode test lamp V.A.G 1527 between sockets 1 (positive) and 2 of plug connector.
Start final control diagnosis and select solenoid valve for activated charcoal filter -N80
=>Page
01-39
.

The diode test lamp should flash.

If the diode test lamp does not flash or lights up continuously:

Connect test box V.A.G 1598/31 to wiring harness for engine control unit. Do not connect to the engine control unit itself.
=> Page
24-14
.

If the diode test lamp lights up continuously:

Test for short to earth in the following wiring connections:

2-pin connector on wiring harness, socket · Test box V.A.G 1598/31, socket
2 · 64

If the diode test lamp does not flash:

Test for short to positive or open circuit in the following wiring connections:

2-pin connector on wiring harness, socket · Test box V.A.G 1598/31, socket
2 · 64

Resistance in wiring: max. 1.5 ω

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

If necessary, rectify short circuit to earth or open circuit.
If no short circuit or open circuit is found ....
Fit a new engine control unit -J220
=> Page
24-17
.