Is there an after market immobilizer fitted? (The Ford immobilizer cuts starter motor function) it sounds like you are getting fuel at initial KEY ON (PCM initializes pump), but then the pump is not kicking in while cranking. You will need to check you are getting power and ground to the fuel pump while cranking.
Fuel pump monitor (models without fuel pump driver module).
The fuel pump monitor (FPM) circuit is spliced into the fuel pump power (fuel pump power) circuit and used by the PCM for diagnostic purposes. The PCM sources a low current voltage down the FPM circuit.
With fuel pump off, voltage is pulled low by the path to ground through the fuel pump. With fuel pump off and the FPM circuit low, the PCM can verify the FPM circuit and fuel pump power circuit are complete from the FPM splice through the fuel pump to ground. This confirms that the fuel pump power or FPM circuits are not shorted to power.
With the fuel pump on, voltage is supplied from the fuel pump relay to the fuel pump power and FPM circuits. With the fuel pump on and FPM circuit high, PCM can verify fuel pump power circuit from fuel pump relay to FPM splice is complete. It can also verify that fuel pump relay contacts are closed and battery voltage is supplied to fuel pump relay.
Fuel pump monitor (models with fuel pump driver module).
The fuel pump driver module (FPDM) communicates diagnostic information to the PCM through the fuel pump monitor (FPM) circuit. This information is sent to the PCM as a duty cycle signal. PCM uses this signal to verify FPDM is powered and able to communicate on the FPM circuit.
Tuesday, February 17th, 2009 AT 3:29 PM