Escape 2WD L4-2.3L VIN Z (2005)
Fuel Pump Signal: Description and Operation
Fuel Pump Monitor (FPM)
Applications Using a Fuel Pump Relay for Fuel Pump On/Off Control
The FPM circuit is spliced into the fuel pump power (FP PWR) circuit and is used by the PCM for diagnostic purposes. The PCM sources a low
current voltage down the FPM circuit. With the fuel pump off, this voltage is pulled low by the path to ground through the fuel pump. With the fuel
pump off and the FPM circuit low, the PCM can verify that the FPM circuit and the FP PWR circuit are complete from the FPM splice through the
fuel pump to ground. This also confirms that the FP PWR or FPM circuits are not shorted to power. With the fuel pump on, voltage is now being
supplied from the fuel pump relay to the FP PWR and FPM circuits. With the fuel pump on and the FPM circuit high, the PCM can verify that the FP
PWR circuit from the fuel pump relay to the FPM splice is complete. It can also verify that the fuel pump relay contacts are closed and there is a B+
supply to the fuel pump relay.
Fuel Pump Driver Module (FPDM) Applications
Fuel Pump Driver Module Duty Cycle Signals
NOTE: The Ford GT uses 2 FPDMs to control fuel for the dual-injection fuel delivery system. The PCM will individually monitor both FPDMs
through their FPM circuits.
The FPDM communicates diagnostic information to the PCM through the FPM circuit. This information is sent by the FPDM as a duty cycle signal.
The 3 duty cycle signals that may be sent are listed in the table.
