Volkswagen Workshop Service and Repair Manuals

Checking fuel pump

Special tools and workshop equipment required

t	Union nut tool -3217-

t	Pressure tester -V.A.G 1318-

t	Adapter -V.A.G 1318/1-

t	Adapter -V.A.G 1318/11-

t	Adapter set -V.A.G 1318/17-

t	Torque wrench (40...200 Nm) -V.A.G 1332-

t	Injection rate comparison meter -V.A.G 1348-

t	Voltage tester -V.A.G 1527B-

t	Adapter set -V.A.G 1594C-

t	Multimeter -V.A.G 1715-

t	Measuring container

t	Current flow diagram

Test prerequisites

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. l  If the vehicle is equipped with an air conditioner, it must be switched off.   Note Observe the functional description of the crash fuel shut-off → Chapter. Checking function and voltage supply   Note Before carrying out further work, battery earth strap may have to be disconnected. First check whether a coded radio is fitted. Obtain radio code first if necessary. –  Fold rear seat forwards. –  Remove cover from fuel delivery unit. –  Switch on ignition. Fuel pump must be heard to run briefly (approx. 1 second). If the fuel pump does not run: –  Switch off ignition. –  Remove fuse holder cover.

–  Remove fuse No. 41 (fuel pump) from fuse holder. –  Connect remote control for V.A.G 1348 -V.A.G 1348/3A- with adapter lead -V.A.G 1348/3-2- to contact 41a of fuel pump and battery positive (+). –  Operate remote control. Fuel pump runs: –  Check activation of fuel pump relay referring to current flow diagram → Current flow diagrams, Electrical fault finding and Fitting locations. Fuel pump does not run: –  Pull 4-pin connector off flange on fuel delivery unit.

–  Connect voltage tester -V.A.G 1527B- to outer contacts of connector using auxiliary cables from auxiliary measuring set -V.A.G 1594C-. –  Operate remote control. LED must light up If LED does not light up: –  Locate and eliminate open circuit referring to current flow diagram → Current flow diagrams, Electrical fault finding and Fitting locations. If LED lights up (voltage supply OK):

–  Unscrew union nut with union nut tool -3217-. –  Check that electrical wires between flange and fuel pump are connected. If no open circuit can be found: –  Renew fuel delivery unit.