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Home >> Chevrolet >> 2005 >> Chevy Express G3500, Van Passenger, LQ4/KL8 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 6.0L (CNG) - Introduction >> Description and Operation >> Fuel Injector Control Module Description >> Notes
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Fuel Injector Control Module Description: Notes

The fuel injector control module (FICM) is a non-flashable control module that is not capable of serial data communication.

The FICM performs the following tasks:

The PCM controls fuel delivery and determines fuel system operation on Bi-fuel (KL6) equipped vehicles. The PCM monitors various engine and vehicle functions to provide the correct amount of CNG or gasoline fuel under all operating conditions. The fuel injector control circuits, an AF Enable circuit and PWM communication circuits connect the PCM to the FICM. The PCM is not capable of operating the high current CNG fuel injectors. The PCM injector pulse width signals are received by the FICM and duplicate pulse width signals are generated by the FICM in order to operate the CNG injectors. KL6 equipped vehicles utilize a FICM that contains internal relays. When operating on gasoline the internal relays allow the PCM injector pulse width to go directly to the gasoline injectors.