Circuit Description

Alternative Fuels Engine Control Module (AF ECM) enables appropriate CNG fuel injector on intake stroke for each cylinder. A voltage is supplied to CNG fuel injectors through a pair of fuel injector relays. AF ECM controls each fuel injector by grounding Control circuit via a solid state device called a driver. A fuel injector coil winding resistance that is too high, or low, will affect engine driveability. A Fuel Injector Control circuit DTC may not set, but a misfire may be apparent. Fuel injector coil windings are affected by temperature. Resistance of fuel injector coil windings will increase as temperature of fuel injector increases.