Audi Workshop Service and Repair Manuals

Note:

Checking fuel pressure, pressure regulator and holding pressure:

=> Motronic injection and ignition system (4-cylinder); Repair Group 24; Servicing Motronic injection system; Testing fuel pressure, fuel pressure regulator and holding pressure

Requirements for test:

• ● Battery voltage not less than 12 V
• ● Fuse No. 28 OK
• ● Fuel filter OK

Test sequence

• ‒ Switch on ignition.

The fuel pump must run audibly (the help of a second mechanic will be required if the surrounding noise level is very high).

If the fuel pump does not run:

• ‒ Switch off ignition.
• ‒ Connect remote control V.A.G 1348/3A with adapter cable V.A.G 1348/3-2 .

• ‒ Operate remote control.

If the fuel pump runs:

• ‒ Test fuel pump relay:

=> Motronic injection and ignition system (4-cylinder); Repair Group 24; Servicing Motronic injection system; Testing fuel pump relay and activation

If the fuel pump does not run:

• ‒ Remove luggage compartment trim.
• ‒ Unbolt cover for flange on fuel tank under floor trim in luggage compartment.
• ‒ Release catch and unplug 4-pin connector.

• ‒ → Use voltmeter to test voltage between contact 1 (green/yellow) and contact 4 (brown).
• ‒ Operate remote control.
• ‒ Specification: approx. battery voltage

If the specification is not attained:

• ‒ Locate and eliminate open circuit using current flow diagram:

=> Current flow diagrams, Electrical fault-finding and Fitting locations

If the specification is attained:

• ‒ Remove union nut with spanner 3217.
• ‒ Remove flange from fuel tank.

• ‒ → Check that the electrical wires between flange and fuel pump are connected and test for continuity.

If no open circuit can be found:

Fuel pump defective.

• ‒ Renew fuel pump .