Checking the fuel pump relay (VW Passat B3)

The fuel pump relay test should only be performed if the fuel pump is not working.

Check fuse #18 of the fuel pump, replace the fuse if necessary.



Remove the fuel pump relay at position #12 on the relay board.

Turn on the ignition and connect the test lamp on the semiconductor diodes between the following contacts: 6 and ground (-), 2 and ground (-), 6 and 4. The prescribed voltage value is approximately the battery voltage (12 volts). Otherwise, find the wire break in accordance with the electrical diagram and fix it.
Turn off the ignition.

Connect the test lamp between contacts 3 and 2.

Turn on the ignition and observe the indicator lamp. The indicator lamp should light for about 1 second and then go out.

Otherwise, find the wire break in accordance with the electrical diagram and fix it; if necessary, replace the control unit.