Volkswagen Touareg 2003 Workshop Repair Manual page 132

Touareg 2003 ➤
8-cylinder injection engine - Edition 11.2011
– Connect vehicle system tester to vehicle.
– Start engine and run at idling speed.
– On vehicle system tester, select operating mode
– Now select diagnostic mode 8 „Tank leak test".
– Select entry „Tank leak test" and press right arrow button
initiate test.
Note
Once the diagnostic mode 8 „Tank leak test" has been acti‐
♦
vated, the leak diagnostic pump and the activated charcoal
filter solenoid valve 2 -N115- are closed for max. 1,000 sec‐
onds. The activated charcoal filter solenoid valve 1 -N80- is
not activated. Now the entire system is closed.
If the engine control unit cancels the test, it is possible to ini‐
♦
tiate it again by switching off and restarting the engine.
– Set valve -D- to „Test". The fuel system will now be filled with
nitrogen.
– Observe pressure gauge -C- and flow meter -E-. When the
throughput quantity decreases and the pressure increases to
25 mbar (10 in. H2O), the fuel system is filled.
Note
Depending on the filling level of the fuel tank, this process can
take up to 3 minutes.
– Once pressure has stabilised, set valve -D- to „Hold".
• After 5 minutes the pressure must not drop below 20 mbar
(8 in. H2O).
If pressure does not drop, exit from diagnostic mode 8 and check
if fuel system diagnostic pump -V144- can build up pressure
⇒ page 129 .
If no pressure builds up or the pressure is not held for at least 5
minutes, localise leak as follows:
Leave engine running at idling speed for at least 8 minutes with
activated diagnostic mode 8.
– First check activated charcoal filter solenoid valve 1 -N80- for
leaks. To do this, clamp off hose to activated charcoal filter
solenoid valve 1 -N80- using a hose clip -arrow-. Also refer to
⇒ Item A (page 128)
126
Rep. gr.20 - Fuel supply system
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OBD
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