If it is necessary to check the fuel injection system with the engine off, pull out the relay and bridge terminal 30 and terminal 87 with a short jumper with a diameter of 1.5 mm. The fuel pump relay is brown on 520i/525i/524td models and orange on 530i/535i models.
Attention: When checking the fuel pump relay, the battery must be charged.
Check fuse no. 23.
Pull out the relay.
Connect voltmeter to terminal 30 (+) and 85 (-) at the relay site. Set value: 12 Volts.
Otherwise, connect a voltmeter to terminal 30 and ground.
If the voltmeter reading is approximately 12 volts, check the brown-green wire for an open in the electrical circuit. If the wire is intact, check the red wire against the wiring diagram and replace if necessary.
Turn on the ignition.
Connect voltmeter to terminal 86 (+) and mass. Set value: about 12 volts. Otherwise, check the red-white wire for an open circuit according to the wiring diagram and replace if necessary.
Check for signals from the speed pulse sensor (service station work).
Short jumper between terminals 30 and 87. If the pump runs, replace the fuel pump relay. Otherwise, ring the green-purple wire at the fuel pump and, if necessary, replace the wire.