DTC U0109: Lost Communication With Fuel Pump Control Module A

WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2011 Mercury Milan, 2011 Mercury Mariner, 2011 Mercury Grand Marquis, 2011 Lincoln Town Car, and 2011 Lincoln Navigator L. However, it is still accessible from the selected car via links, so may be relevant.

U0109 - LOST COMMUNICATION WITH FUEL PUMP CONTROL MODULE A

Description:	The powertrain control module (PCM) monitors the fuel pump monitor (FPM) circuit for the presence of a duty cycled signal. If the FPM circuit is fixed at a low or high voltage, the PCM begins to increment a counter. The test fails when the PCM is still not detecting a duty cycled signal on the FPM circuit after a calibrated amount of time.
Possible Causes:	FPM circuit open or short to ground FPM circuit short to voltage VPWR fuel circuit open PWRGND circuit open Damaged inertia fuel shutoff (IFS) switch (if equipped) Damaged fuel pump control module relay
Diagnostic Aids:	Check if the inertia fuel shutoff (IFS) switch is tripped.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	GO to PINPOINT TEST KC .