Volkswagen CC 2012 Workshop Manual page 65

– Clamp off hose to activated charcoal filter solenoid valve 1 -
N80- using hose clamps, up to Ø 25 mm - 3094- -arrow-.
– Repeat check. If the minimum pressure is reached now, renew
activated charcoal filter solenoid valve 1 - N80- .
If the minimum pressure was again not reached and the available
pressure drops immediately:
– Leak in fuel system: perform "leak detection test in fuel sys‐
tem" ⇒ "5.3.2 Leak detection in fuel system", page 62
If minimum pressure is reached, switch off ignition.
The valve in the fuel system diagnostic pump - V144- is now
closed. The pressure is maintained.
– Observe pressure gauge:
If the pressure does not drop at first, perform a pressure retention
test to localise any tiny leaks
If pressure drops, clamp off hose to activated charcoal filter sol‐
enoid valve 1 - N80- using hose clamps, up to 25 mm in diameter
- 3094- -arrow-.
– If the pressure does not drop again, renew activated charcoal
filter solenoid valve 1 - N80- .
If pressure still drops, perform "leak detection in fuel system" test
⇒ "5.3.2 Leak detection in fuel system", page 62
Pressure retention test
– Set valve -D- to "Test". Increase current pressure to (10 in.
H2O) 25 mbar.
– Observe pressure gauge -C- and flow meter -E-. When flow
rate decreases and pressure increases to 10 in. H2O
(25 mbar), fuel system is filled.
Note
Depending on the filling level of the fuel tank, this process can
take up to 3 minutes.
– Once the pressure has stabilised, set valve -D- to "Hold".
• After 5 minutes, pressure must not drop below 8 in. H2O (20
mbar).
If pressure is not maintained for at least 5 minutes, localise leak
as follows:
CC 2012 ➤ , Passat 2011 ➤ , Passat Variant 2011 ➤
Fuel supply system, petrol engines - Edition 05.2019
⇒ page 61 .
.
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5. Activated charcoal filter with fuel tank leak detection
61