Checking the Fuel Pump Relay

Checking The Fuel Pump Relay












- Turn the ignition switch to the OFF position.
- Remove fuse 28 for 5 seconds.
- Fit fuse 28.







- Turn the ignition switch to the ON position.
- The fuel pump should start and run for 2 seconds.

Is the function correct?

NO - Continue With Checking The Fuel Pump Relay

YES - Checking Fuel Pressure












- Turn the ignition switch to the ON position.
- Contact Trionic 5 OBDII.
- Activate:

Pump Relay
- The fuel pump relay should operate at a frequency of 1 Hz for 10 seconds.

Is the function correct?

NO - Continue With Checking The Fuel Pump Relay

YES - Checking the Fuse - II

Unplug the connector.
- Fuel pump relay (102)












- Connect test lamp 86 11 857 to pins 4 (86) and 5 (85) of the relay holder.







- Turn the ignition switch to the ON position.
- Activate:

Pump Relay
- The test lamp should flash.

Is the function correct?

NO - Continue With Checking The Fuel Pump Relay

YES - Changing Components - III












- Connect test lamp 86 11 857 to pin 4 (86) of the relay holder and a good grounding point.







- The test lamp should light.

Checking the wiring harness.
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short, circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.

Is the function correct?

NO - Rectifying the Lead - XIII

YES - Rectifying the Lead - XIV