Hello.

I have a problem with my pump. Somedays I can hear the pump and the car is working fine, while other days the pump is not working and there is no fuel pumping and the car will not turn on. This has been happening the last 2 weeks. Is the pump the problem or is it the relay or something else?

Thank you,


Senad

 

Fuel Pump, Electrical Checking

Required special tools, testing equipment and auxiliary equipment

VAG1348/3A Remote control using VAG1348/3-2 adaptor cable
Fluke 83 multimeter (or equivalent)
VW 1594A adaptor kit
Test requirements
Battery Voltage: 12 Volts minimum







Fuse 28 OK





Relay 6 in Fuse / Relay panel OK
Fuel filter OK
Ignition switched OFF.
Test sequence
Open fuse box cover on left side of instrument panel.
Remove fuse 28 from fuse panel
Left row, 5th fuse from top







Connect remote control VAG1348/3A on right side of fuse socket 28 using VAG1348/3-2 adaptor wire -arrow-.
Connect clamp to Battery +.
Press remote control switch.
Fuel pump when running must be audible.
NOTE: The fuel pump runs very quietly. Avoid ambient background noise as much as possible during fuel pump checks.

If pump running noise is not audible
Remove connector flange cover under luggage compartment trim.





Unlatch and disconnect 4-pin harness connector -1-.





Switch Fluke 83 multimeter to 20 Volt range
Connect multimeter between terminals 1 (green/yellow) and 4 (brown) of harness connector using jumper wires from VW 1594 adaptor kit.
Press remote control switch continuously and read Voltage.
Specification: approx. Battery Voltage.
If specified value obtained but no audible sound from pump
Remove cover flange as follows
WARNING!
Fuel system is under pressure! Before opening, place clean cloths around the connections to be opened. Carefully loosen the connections to relieve pressure.






Mark return line -2- and supply line -3- and remove from cover flange.





Unscrew union nut using wrench 3217.
Take cover flange and sealing ring out of the fuel tank opening.





Check wiring between flange and fuel pump for continuity.
If wiring OK
Fuel pump faulty, replace.
Fuel supply unit, installing.

 

Fuel Pump Relay And Connections, Checking



The fuel pump relay is located at relay position 4 on the relay panel on the left side under the instrument panel.

Checking function of fuel pump relay -J17-
Remove storage shelf in left-front footwell.




Remove fuses 28, 29 and 34 from fuse panel.
Connect VAG 1527B LED voltage tester between Ground and one of the two terminals for fuse 28.
Briefly crank starter.
LED test light must light up.
Fuel pump relay must be actuated (sound and vibration)
If the fuel pump does not respond:
Check power supply wiring.
If the LED test light does not light up:
Repeat test at other terminal of fuse 28.




If the LED light still does not light up:
Check wiring for open or short circuits between fuse 28 and terminal 30 at relay position 6, using the applicable wiring diagram. Repair wiring as necessary.




Connect VAG 1527B LED voltage tester between Ground and one of the two terminals for fuse 29.
NOTE: This step lets the fuel pump run without the engine running. The closed throttle position switch must be closed during the test, or the selected fuel injector will discharge fuel when it is actuated 5 times.

Initiate output Diagnostic Test Mode (DTM) and advance to test of cylinder 1 fuel injector -N30-. Refer to "Oxygen Sensor Behind Catalyst/Sensor and Sensor Control"
LED test light must light up
Fuel pump relay must be activated
Fuel pump must run
If the LED test light does not light up:
Repeat test at other terminal of fuse 29.




If the LED test light does not light up:
Check wiring for open circuit between fuse 29 and terminal 30 at relay position 6, using the applicable wiring diagram. Repair wiring as necessary.





Connect VAG 1527 LED voltage tester between Ground and one of the two terminals of fuse 34.
NOTE: This step lets the fuel pump run without the engine running. The closed throttle position switch must be closed during the test, or the selected fuel injector will discharge fuel when it is actuated 5 times.

Initiate output Diagnostic Test Mode (DTM) and advance to test of cylinder 1 fuel injector -N30-. Refer to "Oxygen Sensor Behind Catalyst/Sensor and Sensor Control"
LED test light must light up
Fuel pump relay must be activated
Fuel pump must run
If the LED test light does not light up:
Repeat test at other terminal of fuse 34.





If the LED test light does not light up:
Check wiring for open circuit between fuse 34 and terminal 31 at relay position 6, using the applicable wiring diagram. Repair wiring as necessary.
Checking fuel pump relay voltage supply
Remove fuel pump relay -J17- from relay panel position 6.
Switch ignition on.
Connect multimeter US 1119 (Fluke 83 or similar) and check for voltage at relay socket:
Terminals 28 (B+) and 34
Terminals 32 (B+) and 34
Specified values: approx. Battery Positive Voltage (B+)
If voltage is NOT OK:
Repair wiring according to applicable wiring diagram.
Checking fuel pump relay signal
Fuel pump relay -J17- removed
Fuses 28, 29 and 34 removed from fuse panel





Connect VAG 1527B LED voltage tester between relay socket terminals 28 (B+) and 29. LED test light must light up (dimly).
Briefly crank starter; LED test light must continue to light up (dimly).
If the LED test light does not light up while cranking the starter, check wiring as follows.





Connect VAG 1598/22 test box to ECM harness connector. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1598/22 Test Box" See: Computers and Control Systems\Testing and Inspection (Numbers marked on ECM connector match those on test box).
Connect multimeter US 1119 (Fluke 83 or equivalent) to check for open circuit between relay socket terminal 29 and test box socket 4. Specified value: max. 1 Ohms
If resistance is NOT OK:
Repair wiring using applicable wiring diagram.
If the wiring is OK, but the LED test light does not light up:
Replace Engine Control Module (ECM).
If the wiring is OK, and the signal to the fuel pump relay is OK:
Replace fuel pump relay -J17-.
Reinstall fuses.

 

I have an audi a4 1.8T b5 quattro 1999. what location is the fuel pump relay? the relays i have on my panel are 387, 377, 370, 204 and 267.

You have written J17- however I do not have a J17 relay???

Thank you,

Senad

 

#4 is the relay - its on the driveside