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Table of Contents > Repairing fuel supply system (Golf, Eos, Scirocco) > Checking fuel pump G6

VW Passat B6 Service Manual ➜ Checking fuel pump G6

CC 2010 ➤ , Eos 2006 ➤ , Golf 2004 ➤ , Golf 2009 ➤ , Passat 2006 ➤ , ...  
4-cyl. injection engine (1.8 and 2.0 l engine, chain drive) - Edition 08.2018  
– If the sender cannot be released in this way, the retaining tabs  
-arrows- must also be pushed to the side slightly.  
– Note colour co-ordination of cables for reinstallation.  
– Release electrical connectors -1 to 3- and pull them off. Then  
bend back locking lugs of connectors.  
Installing:  
– Connect connectors -1…3-. Observe colour co-ordination.  
– Check connectors are secured properly by pulling.  
– Insert fuel gauge sender - G- into guide on fuel delivery unit  
and press down until it engages.  
– Install fuel delivery unit ⇒ page 346 .  
8.3  
Checking fuel pump - G6-  
350  
Rep. gr.20 - Fuel supply system  
CC 2010 ➤ , Eos 2006 ➤ , Golf 2004 ➤ , Golf 2009 ➤ , Passat 2006 ➤ , ...  
4-cyl. injection engine (1.8 and 2.0 l engine, chain drive) - Edition 08.2018  
Special tools and workshop  
equipment required  
♦ Pressure gauge - VAS 6550-  
♦ Remote control - V.A.G 1348/3A-  
♦ Test instrument adapter/DSO (5-pin) - VAS 5565-  
♦ Multimeter - V.A.G 1715-  
♦ Special wrench - T10202-  
♦ Torque wrench - V.A.G 1332-  
♦ Measuring container, capacity: 3 litres  
8.3.1  
Checking function and voltage supply  
Test conditions:  
Battery voltage at least 11.5 V.  
Fuse for Fuel pump control unit - J538- OK.  
Fuel pump control unit - J538- OK.  
8. Repairing fuel supply system (Golf, Eos, Scirocco)  
351  
CC 2010 ➤ , Eos 2006 ➤ , Golf 2004 ➤ , Golf 2009 ➤ , Passat 2006 ➤ , ...  
4-cyl. injection engine (1.8 and 2.0 l engine, chain drive) - Edition 08.2018  
Test sequence  
Note  
Function of fuel pump is checked using final control diagnosis.  
If the final control diagnosis is to be carried out several times  
in succession, it may be necessary to start the engine briefly  
before repeating the final control diagnosis.  
– Connect vehicle diagnostic tester as follows:  
– Push diagnosis cable connector onto diagnosis connection in  
driver footwell.  
– Switch ignition on.  
– Press buttons on display one after the other for Vehicle  
self-diagnosis, Engine electronics and Final con-  
trol diagnosis.  
– Press right arrow button on display up to final control diag‐  
nosis for fuel pump electronics.  
The fuel pump must now run slowly up to maximum speed.  
Note  
The fuel pump runs very quietly.  
– Switch off ignition.  
If fuel pump does not run:  
– Remove bench seat ⇒ General body repairs, interior; Rep. gr.  
72 ; Removing and installing bench seat .  
– Pull connector off fuel pump control unit - J538- .  
– Check voltage supply between contacts -1- and -6- using mul‐  
timeter - V.A.G 1715- .  
Specification: approx. battery voltage  
Voltage supply not OK:  
– Locate and eliminate open circuit referring to current flow di‐  
agram ⇒ Current flow diagrams, Electrical fault finding and  
Fitting locations.  
Voltage supply OK:  
352  
Rep. gr.20 - Fuel supply system  
CC 2010 ➤ , Eos 2006 ➤ , Golf 2004 ➤ , Golf 2009 ➤ , Passat 2006 ➤ , ...  
4-cyl. injection engine (1.8 and 2.0 l engine, chain drive) - Edition 08.2018  
– Remove cover -1- with fuel pump control unit - J538- -2- from  
fuel delivery unit.  
– First check that the connector -arrow- is fitted securely by pull‐  
ing the connector without pressing the catch. If connector was  
not inserted correctly, repeat functional check of fuel pump.  
– Now pull off connector.  
– Check the contacts on the connector and on the fuel delivery  
unit for damage.  
WARNING  
Fuel supply line is pressurised. Wear protective goggles and  
protective clothing to avoid injury and contact with the skin.  
Wrap a cloth around the connection before loosening hose  
connections. Then release pressure by carefully pulling hose  
off connection.  
– Pull fuel lines -1- and -2- off the flange.  
Note  
Press in securing ring to release the fuel lines.  
On vehicles with auxiliary heater, the connector and the fuel  
line of the metering pump - V54- must also be disconnected.  
– Open locking ring using key - T10202- .  
Caution  
Do not cant key - T10202- and press against locking ring firmly.  
If the key slips off, the fuel delivery unit can be damaged.  
– Check that electrical wires between flange and fuel pump are  
connected.  
If no open circuit can be found:  
– Fuel pump defective, renew fuel delivery unit ⇒ page 346 .  
8. Repairing fuel supply system (Golf, Eos, Scirocco)  
353  
CC 2010 ➤ , Eos 2006 ➤ , Golf 2004 ➤ , Golf 2009 ➤ , Passat 2006 ➤ , ...  
4-cyl. injection engine (1.8 and 2.0 l engine, chain drive) - Edition 08.2018  
8.3.2  
Checking fuel pressure  
Note  
The fuel pressure must be checked by means of the final con‐  
trol diagnosis. If the fuel pressure is measured at idling speed,  
it may deviate from the specification.  
If the final control diagnosis is to be carried out several times  
in succession, it may be necessary to start the engine briefly  
before repeating the final control diagnosis.  
WARNING  
Fuel supply line is pressurised. Wear protective goggles and  
protective clothing to avoid injury and contact with the skin.  
Wrap a cloth around the connection before loosening hose  
connections. Then release pressure by carefully pulling hose  
off connection.  
– Pull off supply line (metal coupling) -arrow- and catch escaping  
fuel with a cloth.  
Note  
Press in securing ring to release fuel line.  
– Connect pressure tester - VAS 6550- to fuel supply line with  
adapter - VAS 6550/1- and -VAS 6550/2- .  
– Make sure that drain tap is closed and cut-off taps are open.  
– Actuate fuel pump with final control diagnosis to build up fuel  
pressure.  
– Read fuel pressure on pressure gauge.  
Specification: 4.0 to 7.0 bar  
If fuel pressure is OK, check holding pressure ⇒ page 358 .  
If the specification is exceeded:  
– Check return line between fuel filter and fuel pump for kinks  
and blockages.  
If no fault is found:  
– Pressure limit valve in fuel filter is defective. Renew fuel filter.  
If specification is not obtained  
– Check fuel pressure upstream of fuel filter; proceed as follows:  
354  
Rep. gr.20 - Fuel supply system