Removal, installation and checking the fuel pump relay (BMW 3 Series E46)

The fuel pump relay is located on the relay holder behind the fuse box. It supplies the fuel pump with electrical current. Via a safety switch, it interrupts the fuel supply when no rev pulses are sent when the ignition is on, for example when the engine stalls.

If it is necessary to turn on the fuel pump when the engine is not running to check the injection system, disconnect the relay and connect terminals 30 and 87b with a short auxiliary cable. The wire diameter should be 1.5 mm.

Removal

1. Remove the glove box, refer to Section Removal and installation the left glove compartment and Removal and installation the right glove compartment.

2. Use a small screwdriver to remove the backlight lamp from the side and disconnect the connector.



3. Unscrew the screws (arrows in the illustration) and remove cover "1" downwards. From the back of the cover, remove the glove compartment light wire.





4. Press cover "1" back a little and remove it from guides "2". Disconnect the brackets in area "3".



5. Unscrew the screw (arrow on the illustration) and move the relay holder down a little.

6. Remove fuel pump relay "1".

Examination

7. Check the injection system fuse. The location of the fuses is shown in the diagram in the fuse box.



8. Remove relay "3". Connect terminals 30 and 87b with a short auxiliary wire (diesel engine: terminal 87). Be careful not to damage the relay's sensitive contacts. If you can hear the fuel pump turning on, replace the relay.



9. If the pump does not work, check the wires going to the relay and the pump. Replace if necessary.

10. Check relay/fuel pump.

Installation

11. Reinstall the relay.



12. Tilt the relay holder up and secure with the screw.



13. Insert the cover into the guides.



14. Route the wire to the glove box light from the back of the top cover. Secure the cover.



15. Attach the backlight lamp and secure it.

16. Replace the glove box, refer to Sections Removal and installation the left glove compartment and Removal and installation the right glove compartment.