2. Turn on the ignition. The fuel pump should run audibly.
3. Turn off the ignition.
If the fuel pump is not working
4. First check if the wiring harness connector is installed correctly (arrow). Pull the wiring harness connector without pressing the tabs. An incorrectly installed wiring harness connector may cause a malfunction.
5. Disconnect the wiring harness connector (arrow), shown in the figure below.
6. Connect adapter for measuring technology/digital oscilloscope with memory (5 pin) -VAS 5565- Between wiring harness connector and flange.
7. Connect hand-held multimeter -VAG 1526D- to test contacts (1) And (5) adapter as shown in the figure below.
8. Connect diagnostic, measuring and information system -VAS 505x- and carry out the function "Test fuel pump".
Note. The fuel pump will be activated for 30 seconds.
9. Read off the voltage value from the hand-held multimeter -VAG 1526D. Required value: approximately equal to the battery voltage.
No voltage was measured
10. Check arousal (activation) fuel pump relay.
11. Check wires for breakage and short circuit.
Supply voltage OK
12. Remove the fuel pump.
13. Check whether the electrical wires are connected between the flange and the fuel pump and their permeability.
Cables are OK
14. Replace fuel pump assembly.