Volkswagen Touareg (2003 year). Manual - part 28

Checking delivery quantity of right pump

– Connect remote control -V.A.G 1348/3 A- with adapter cable

- Phaeton -V.A.G 1348/3-3- to connection -arrow- of fuel pump

relay for right fuel delivery unit.

– Connect positive terminal of remote control to positive pole in

engine compartment.

– Disconnect fuel supply hose -1- from fuel rail.
– Hold hose in measuring container -2- with minimum capacity

of 1000 cm

3

.

– Empty measuring container before making measurement.
– Operate remote control for 15 seconds. At least 800 cm

3

 fuel

per 15 seconds must be delivered.

1.11.2

Checking delivery quantity of left pump

– Connect remote control -V.A.G 1348/3 A- with adapter cable

- Phaeton -V.A.G 1348/3-3- to connection -arrow- of fuel pump

relay for left fuel delivery unit.

– Empty measuring container before making measurement.
– Operate remote control 15 seconds again. At least 800 cm

3

fuel per 15 seconds must be delivered.

– In addition, check both fuel delivery units.
– To do so, connect adapter cable - Phaeton -V.A.G 1348/3-3-

to connections of relays for left and right fuel delivery units.

– Empty measuring container before making measurement.
– Operate remote control 10 seconds. At least 800 cm

3

 fuel per

10 seconds must be delivered.

If the minimum delivery rate is not attained during one of the tests:
– Check fuel lines for possible restrictions (kinks) or blockages.
If fuel lines are ok:
– Renew fuel filter.
If delivery rate has been attained, but nevertheless you suspect

a fuel supply system fault (e.g. intermittent failure of fuel supply

system):
– Check current draw of fuel pumps 

⇒ page 109

 .

1.11.3

Checking current draw of pumps

– Check current draw of each fuel pump separately as follows:
– Reconnect all disconnected fuel lines.

Touareg 2003 ➤

1. Parts of fuel supply system    

109

-arrows-.

– Remove nuts -1- from cover. If necessary, unscrew backrest

mounting -2- or support mounting ⇒  General body repairs,

interior; Rep. gr.  72 ; Rear seats .

Touareg 2003 ➤

110

pin connector contact -1- -arrow- of wiring harness to right fuel

delivery unit.

Note

The hand-held multimeter -V.A.G 1526D- with pickup clamp -

V.A.G 1526B/2- can also be used.

– Start engine and run at idling speed.
– Measure current draw of fuel pump. Specification: max. 11

amps.

If current draw is exceeded:
– Right fuel pump is defective. Renew fuel delivery unit

⇒ page 102

 .

– Repeat test on left fuel delivery unit.
If current draw is exceeded:

WARNING

Fuel supply lines are under pressure! Wear eye protection and

gloves  to  avoid  injuries  and  skin  contact.  Before  loosening

hose connections, wrap a cloth around the connection. Then

release pressure by carefully pulling hose off connection.

– Left fuel pump is defective. Renew fuel delivery unit.

Note

If the fuel system malfunction is intermittent, you can perform the

check during a road test, but a 2nd person is necessary.

1.12

Checking non-return valve of right pump

Test prerequisites
• Fuel pump relays -1- for right fuel delivery unit and -2- for left

fuel delivery unit must be removed from their sockets.

Touareg 2003 ➤

1. Parts of fuel supply system    

111

-T10202- .

– Carefully lever flange and raise it slightly.
– Disconnect connectors next to fuel filter.

– Then detach fuel supply hose -2- leading from right fuel deliv‐

ery unit from fuel filter -1-.

– Allow fuel from connection -1- to flow back into fuel tank.

– Close pressure gauge shut-off tap (lever at right angles to di‐

rection of flow).

– Connect pressure tester -V.A.G 1318- with adapter -

V.A.G 1318/7- , adapter -V.A.G 1318/13- and adapter -

V.A.G 1318/17- as shown.

Note

Ensure that fuel supply line connection engages audibly when

joined.

Touareg 2003 ➤

112