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

Special tools and workshop equipment required

V.A.G 1526 A
V.A.G 1527 B
V.A.G 1594 A
V.A.G 1598 A
V.A.G 1598/3
VAS 5051 with VAS 5051/1 and VAS 5051/2

or

V.A.G 1551 with V.A.G 1551/1

Fitting location => Fitting locations overview, Page
25-5

Note:

The activated charcoal filter system solenoid valve 1 is also referred to in this context as fuel tank breather valve of ACF valve.

Testing for leaks

Solenoid valve for ACF -N80 remains closed when de-energised.

Disconnect hoses from ACF valve but leave the electrical connector plugged in.
Connect auxiliary hose to one connection of ACF valve.
Start final control diagnosis =>Page
01-32
and actuate solenoid valve for ACF -N80.

Final control diagnosis
⇒
Solenoid valve 1 for activated charcoal filter N80
When adjacent display appears:

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

If valve does not open and close properly:

Fit a new ACF valve.

If the cold start valve does not react with final control diagnosis:

Checking internal resistance to ACF valve.

Checking internal resistance

Unplug connector on ACF valve.
Connect multimeter to injector to measure resistance.
Specification: 18 ... 26 ω

If the specification is not obtained:

Fit a new ACF valve.

Checking power supply

Test requirements:

Fuse S75 in brown holder in electronics box in passenger footwell OK

Unplug connector on ACF valve.

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

Connector / Contact · Measure to
1 · Engine earth

Switch the ignition on.
The LED should light up.

If the LED does not light up:

Eliminate open circuit or short circuit using the current flow diagram.

Checking actuation

Unplug connector on ACF valve.
Connect up voltage tester V.A.G 1527 B between contacts 1 and 2.
Start final control diagnosis and actuate ACF valve => Page
01-32
.
The LED should flash.

If LED does flash:

Fit a new ACF valve.

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

With the ignition switched off, use adapter V.A.G 1598/3 to connect test box V.A.G 1598 A to plug connection of engine control unit (control unit remains disconnected) => Page
25-9
.

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

Connector / Contact · Test box V.A.G 1598 A / Socket
2 · 15

Rectify any open/short circuit as necessary.

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

If wiring is OK and no activation occurs:

Replace engine control unit => Page
25-12
.