i haave a problem with my fuel pump ......when i turn the key on there is no noise coming from the pump, but when i hook my scanner up to it and activate the fuel pump it works!?? My relays are working but there is no voltage going to the pump......any ideas

 

The pump only operates when the engine is cranking over to start or running.

 

TY for replying Toyomoho ,doesn't the pump turn on a couple of seconds before cranking to pressurize the system

 

Pump only turns on as specified previously.

The system has a check valve that prevents bleed down when off. However over time the system can pressure can drop. Typically re-pressuring the system is not a problem when starting. Cars sitting for months and months start right up.