So, if no power to fuel pump then your SES light is on in the dash right? You need to find out what codes have been set in the ecm. Lots of reasons the fuel pump is shutting down, not likely its just not getting power due to failed part; more likely the ecm is shutting it down for a reason.
Normal operation is to operate for 2 sec when you first turn key to run postion. You should be able to hear that without starting car. Have you given a listen for the pump?
After 2 sec, and no engine rpm, the pump shuts off.
Even if pump has failed, then engine won't start, fuel pump power shuts down after 2 sec, and when you go try to measure pump for power, there won't be any . . .
Need to get ecm codes, or need to measure power to fuel pump before, during, after turning key from off to run position.