Get Fuel supply system -> 4.2 Checking fuel system for leaks Guide for Volkswagen Touareg SUV First Generation (2002-2010)

Touareg 2003 ➤

8-cylinder injection engine - Edition 11.2011

14 - Securing bolts

❑ Qty. 3

❑ 9 Nm

15 - Breather line

❑ To vacuum connection on intake manifold

❑ Check for secure seating.

16 - Connector

❑ Black, 2-pin.

17 - Activated charcoal filter solenoid valve 1 -N80-

❑ Note installation position.

18 - Rubber bracket

❑ Note installation position.

19 - Breather line

❑ Check for secure seating.

20 - Pressure retention valve

❑ Function ⇒ page 124 .

Function of pressure retention valve

From gravity valve (on expansion tank) the pressure retention

valve is open in both directions of flow. -Arrow 1- is the side to

expansion tank.

lk

On the other side it is only open for flow in one direction.

-Arrow 2- is the side to activated charcoal filter.

4.2

Checking fuel system for leaks

Special tools and workshop equipment required

♦ Fuel system tester (so-called smoke tester) -KLI 9210-

♦ Adapter hose -KLI 9210/55-2-

♦ Vehicle diagnosis tester -VAS 5051B- , -VAS 5052- or -VAS

5053-

♦ Hose clamps up to 25 mm -3094-

Test prerequisite:

•

A leak has been detected by the fuel system diagnostic pump

-V144- .

•

Guided fault finding has been performed with the vehicle di‐

agnosis tester .

Preparation of fuel system tester -KLI 9210- :

Note

The fuel system tester -KLI 9210- may differ in appearance de‐

pending on the version.

124

Rep. gr.20 - Fuel supply system

Touareg 2003 ➤

8-cylinder injection engine - Edition 11.2011

– Check on fuel system tester -KLI 9210- if there is enough fluid

in smoke generator.

– Set valve -D- to „Hold“.

– Open nitrogen bottle -H-.

– Connect test hose -G- to self-test connection -B-.

lk

– Set valve -D- to „Test“.

– Regulate pressure to 25 mbar (10 in. H2O) with pressure re‐

ducer -J-.

– Set valve -D- to „Hold“.

– Now pressure must be maintained for at least 2 minutes.

Check tester if pressure is not maintained.

Checking fuel system for leaks:

– Pull off rear engine cover -arrows-.

– In engine compartment, disconnect breather line -arrow- to

activated charcoal filter solenoid valve 1 -N80- .

– Connect adapter hose -KLI 9210/55-2- between activated

charcoal filter solenoid valve 1 -N80- and breather line -A- as

shown in illustration.

– Connect measuring hose -G- from fuel system tester -KLI

9210- to adapter hose -KLI 9210/55-2- .

– Connect fuel system tester -KLI 9210- to vehicle battery.

4. Activated charcoal filter system (vehicles for USA and Canada)

125

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 OBD .

– Now select diagnostic mode 8 „Tank leak test“.

– Select entry „Tank leak test“ and press right arrow button ► to

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.

lk

♦ 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

Touareg 2003 ➤

8-cylinder injection engine - Edition 11.2011

– Repeat pressure test by setting valve -D- again to „Test“.

– Observe pressure gauge and flow meter. When the through‐

put quantity decreases and the pressure increases to 25 mbar

(10 in. H2O), the fuel system is filled.

– Once pressure has stabilised, set valve -D- to „Hold“.

– If the pressure does not drop again, renew activated charcoal

filter solenoid valve 1 -N80- .

If pressure still drops:

– Set valve -D- again to „Test“.

– While fuel system is being filled, press button -I- for smoke

generator for approx. one minute.

The fuel system is now pressurised and filled with smoke.

– Check whether smoke escapes from any visible fuel system

line or hose. Also check fuel tank cap.

Note

♦ Light up the components and hoses with a strong floodlight. In

the floodlight, smoke is more visible.

♦ For leak detection in accessible areas, also use ultrasonic de‐

tector or commercially available leak detecting spray.

♦ Depending on how long the fault finding takes, it may be nec‐

essary to press the smoke generator button from time to time.

This ensures that sufficient smoke is present in the fuel sys‐

tem.

If no fault is found:

– Remove rear right wheel housing liner.

If smoke escapes from air filter ⇒ Item _l7_k(page 128) :

– Clamp off hose between activated charcoal filter solenoid

valve 2 -N115- and air filter -arrow-. Also refer to

⇒ Item B (page 128) .

– Observe air filter. If smoke no longer escapes, activated char‐

coal filter solenoid valve 2 -N115- is leaking. Renew activated

charcoal filter system solenoid valve 2 -N115- .

4. Activated charcoal filter system (vehicles for USA and Canada)

127

Touareg 2003 ➤

8-cylinder injection engine - Edition 11.2011

If smoke still escapes from air filter:

– Clamp off hose between fuel system diagnostic pump -V144-

and air filter -arrow-. Also refer to ⇒ Item C (page 128) .

– Observe air filter. If smoke no longer escapes, shut-off valve

in fuel system diagnostic pump -V144- is leaking. Renew fuel

system diagnostic pump -V144- .

If no smoke escapes from air filter ⇒ Item 7 (page 128) :

– Check whether smoke escapes from any fuel system compo‐

nent or hose.

To inspect flanges for fuel pump and fuel filter, open assembly

openings in vehicle interior.

– Renew leaking hoses or components.

After completing work, perform guided function „checking fuel

tank breather system for leaks“ using ⇒ Vehicle diagnostic tester.

4.2.1

Overview of activated charcoal filter system

1 - Activated charcoal filter

2 - Location of adapter hose -

KLI 9210/55-2-

❑ For leak detection in fuel

system

3 - Activated charcoal filter sol‐

enoid valve 1 -N80-

4 - Breather line

❑ To intake manifold.

lk

5 - Solenoid valve

❑ For fuel system diag‐

nostic pump -V144-

6 - Vacuum line

❑ To intake manifold.

7 - Air filter

❑ For fuel system diag‐

nostic pump -V144-

8 - Fuel system diagnostic

pump -V144-

9 - Fuel tank

10 - Cap

11 - Activated charcoal filter

solenoid valve 2 -N115-

12 - Pressure retention valve

A - Clamp off in this area

❑ For leak detection in fuel

system

❑ For checking activated

charcoal filter solenoid

valve 1 -N80- .

B - Clamp off in this area

❑ For leak detection in fuel system

❑ For checking activated charcoal filter solenoid valve 2 -N115- .

128

Rep. gr.20 - Fuel supply system

Touareg 2003 ➤

8-cylinder injection engine - Edition 11.2011

C - Clamp off in this area

❑ For leak detection in fuel system

❑ For checking fuel system diagnosis pump -V144- .

4.2.2

Checking build-up of pressure of fuel

system diagnostic pump -V144-

Test prerequisite:

•

Fuel system tester -KLI 9210- is connected to vehicle via

adapter hose -KLI 9210/55-2- .

•

Valve -D- is set to „Hold“.

Diagnostic mode 8 is completed and engine is running at idling

speed.

Fuel system must not be under pressure for test. Proceed as fol‐

lows to reduce residual pressure:

– Briefly open quick-release coupling -arrow- for adapter hose -

KLI 9210/55-2- to release pressure in fuel system. Pressure

gauge -D- must drop to 0 in. H2O.

– On vehicle system tester, select operating mode Guided

lk

functions .

– Select guided function „Checking tank ventilation system for

leaks“.

– Initiate test.

– Observe pressure gauge while test is running.

– Fuel system diagnostic pump -V144- must pump up pressure

in fuel system at least to 18 mbar (7 in. H2O).

– If pressure is not reached, check vacuum supply of fuel system

diagnostic pump -V144- ⇒ page 129 .

– If fuel system is free of leaks and vacuum supply of fuel system

diagnostic pump -V144- is OK, renew fuel system diagnostic

pump -V144- .

4.2.3

Checking vacuum supply of fuel system

diagnostic pump -V144-

Special tools and workshop equipment required

4. Activated charcoal filter system (vehicles for USA and Canada)

129

Touareg 2003 ➤

8-cylinder injection engine - Edition 11.2011

♦ Turbocharger tester -V.A.G 1397A-

♦ T piece -251 201 346-

♦ Hose ∅ 6 mm

lk

Note

Fitting location of fuel system diagnosis pump -V144- : in rear right

wheel housing under wheel housing liner.

– Remove rear right wheel and wheel housing liner.

– Remove securing bolts ⇒ Item 14 (page 123) of activated

charcoal filter and lower filter to have better access to vacuum

line.

Caution

Support activated charcoal filter to prevent its hanging down

from hoses and lines. This prevents damages.

– Disconnect vacuum line -1- from fuel system diagnostic pump

-V144- .

– Connect turbocharger tester -V.A.G 1397A- with T-piece and

hose ∅ 6mm, between vacuum line -1- and fuel system diag‐

nostic pump -V144- -2-.

– Switch on measuring range I (absolute pressure measure‐

ment).

– Connect vehicle diagnosis tester and start engine.

– On vehicle diagnosis tester, select operating mode Guided

functions .

– Select guided function „Checking tank ventilation system for

leaks“.

– Observe display on turbocharger tester -V.A.G 1397A- while

test is running.

•

Pressure must pulsate and must not exceed 0.700 bar during

test.

– If pressure exceeds 0.7 bar during test, vacuum supply is too

low. Check vacuum line to intake manifold for possible kinks

or blockages.

130

Rep. gr.20 - Fuel supply system

Fuel supply system -> 4.2 Checking fuel system for leaks for Your Volkswagen Touareg SUV First Generation (2002-2010)

Related Topics

Fuel supply system

Popular Owner Manuals

Latest Owner Manuals