Liberty 4WD V6-3.7L (2009)
Fuel Injector: Description and Operation
PCM Output
PCM OUTPUT
The nozzle ends of the injectors are positioned into openings in the intake manifold just above the intake valve ports of the cylinder head. The engine
wiring harness connector for each fuel injector is equipped with an attached numerical tag (INJ 1, INJ 2 etc.). This is used to identify each fuel injector
with its respective cylinder number.
The injectors are energized individually in a sequential order by the Powertrain Control Module (PCM). The PCM will adjust injector pulse width by
switching the ground path to each individual injector on and off. Injector pulse width is the period of time that the injector is energized. The PCM will
adjust injector pulse width based on various inputs it receives.
Battery voltage (12 volts +) is supplied to the injectors through the ASD relay. The ASD relay will shut-down the 12 volt power source to the fuel
injectors if the PCM senses the ignition is on, but the engine is not running. This occurs after the engine has not been running for approximately 1.8
seconds.
The PCM determines injector on-time (pulse width) based on various inputs.
