Note. The performance of the fuel pump is checked as part of the diagnosis of the regulatory bodies.
1. Connect diagnostic, measuring and information system -VAS 505X-.
2. Turn on the ignition.
3. On the display, press the buttons gradually to "car automatic control systems", "01 - engine electronics" And "03 - Diagnosis Regulators".
4. Press the right arrow on the display until the fuel pump electronics regulator diagnosis appears. The fuel pump should slowly accelerate up to maximum speed.
The fuel pump runs quietly.
5. Turn off the ignition.
Fuel pump does not work:
6. Remove the rear seat (for more details, see the relevant section in chapter Body).
7. Disconnect the wiring harness connector (3) from the fuel pump control unit -J538- as shown in the figure below.
8. Check the voltage supply with a voltage tester (test lamp on semiconductor diodes) -VAG 1527B- between contacts (1) And (6), as shown in the figure below. The light emitting diode should be on.
Light emitting diode is off
9. Identify and eliminate a wire break according to the circuit diagram of electrical equipment.
Light emitting diode on (power supply is ok)
10. Release the cover from the clamps (4) together with fuel pump control unit -J53B- (1), as shown in the figure below.
11. First, check the correct installation of the wiring harness connector (1), which is shown in the figure below. To do this, pull the wiring harness connector without pressing the latches.
If the wiring harness connector was installed incorrectly
12. Repeat the control of the fuel pump.
If the wiring harness connector was installed correctly
13. Disconnect the wiring harness connector (1).
14. Check the integrity of the contacts at the connector of the wiring harness and at the fuel pump.
If no damage was found
15. Remove the fuel pump (see relevant section in this chapter).
16. Check the connection of electrical wires between the flange and the fuel pump.
If no broken wires are found
17. The fuel pump is faulty. Replace fuel pump assembly.