U0109 – Lost Communication With Fuel Pump Control Module

U0109 Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

U0109 Possible Causes

Fuel pump monitor circuit open or short to ground,Fuel pump monitor circuit short to voltage,Damaged Inertia Fuel Shutoff (IFS) switch (if equipped),Damaged fuel pump control module relay

U0109 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.