volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

Checking tandem pump > < Installing
Checking fuel pump
Checking fuel pump
Special tools and workshop equipment required
   
t  Hand multimeter -V.A.G 1526 B- or multimeter -V.A.G 1715-
  W00-0573
t  Voltage tester -V.A.G 1527 B-
t  Adapter set -V.A.G 1594 C-
Test prerequisite
l  Fuses must be OK.
l  The battery voltage must be at least 11.5 V.
l  All electrical consumers, e.g. lights and rear window heating, must be switched off.
Checking function and voltage supply
–  Remove rear seat bench → General body repairs, interior; Rep. Gr.72.
–  Remove cover from fuel delivery unit.
–  Switch on ignition. The fuel pump must be heard to run for about 2 seconds.
–  Switch off ignition.
If the fuel pump does not start
–  Pull 5-pin connector off fuel delivery unit flange.
  W00-0513
–  Connect voltage tester -V.A.G 1527 B- to outer contacts of connector using auxiliary cables from auxiliary measuring set -V.A.G 1594 C-.
–  Switch on ignition. The LED must light up for about 2 seconds.
–  Switch off ignition.
If LED does not light up
–  Check actuation of fuel pump relay and wiring for open circuit or short circuit. → Vehicle diagnosis, testing and information system VAS 5051
If LED lights up (voltage supply OK)
–  Remove fuel delivery unit → Chapter.
–  Check that electrical wiring between flange and fuel pump is connected and has continuity.
If no open circuit can be found
–  Renew fuel delivery unit → Chapter.
Checking current consumption of fuel pump
–  Pull 5-pin connector off fuel delivery unit flange.
  N20-10045
–  Set multimeter to measuring range 20 A and connect in series between contacts -1- of connector and fuel pump using auxiliary cables from auxiliary measuring set -V.A.G 1594 C-.
  Note
The current pick-up clamp of multimeter -V.A.G 1715- can also be attached to an auxiliary cable between contacts -1- of connector and fuel pump.
–  Connect contacts -5- of connector and fuel pump using an auxiliary cable from auxiliary measuring set -V.A.G 1594 C-.
–  Start engine and run at idling speed.
–  Measure current draw of fuel pump: Specification: max. 7.5 Amperes.
–  If the values measured lie outside the specifications
–  Renew fuel delivery unit → Chapter.
  N20-10105

Checking tandem pump > < Installing