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EC-36 < FUNCTION DIAGNOSIS > [VQ40DE] MULTIPORT FUEL INJECTION SYSTEM MULTIPORT FUEL INJECTION SYSTEM System Description INFOID:0000000005257035 INPUT/OUTPUT SIGNAL CHART *1: This sensor is not used to control the engine system under normal conditions. SYSTEM DESCRIPTION The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the ECM memory. The program value is preset by engine operating conditions. These conditions are determined by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air flow sensor. VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION In addition, the amount of fuel injected is compensated to improve engine performance under various operat- ing conditions as listed below. <Fuel increase> • During warm-up • When starting the engine • During acceleration • Hot-engine operation • When selector lever is changed from N to D • High-load, high-speed operation <Fuel decrease> • During deceleration • During high engine speed operation Sensor Input Signal to ECM ECM function Actuator Crankshaft position sensor (POS) Engine speed* 3 Piston position Fuel injection Fuel injector Camshaft position sensor (PHASE) Mass air flow sensor Amount of intake air Engine coolant temperature sensor Engine coolant temperature Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas Throttle position sensor Throttle position Accelerator pedal position sensor Accelerator pedal position TCM Gear position Knock sensor Engine knocking condition Battery Battery voltage* 3 Power steering pressure sensor Power steering operation Heated oxygen sensor 2* 1 Density of oxygen in exhaust gas Air conditioner switch Air conditioner operation* 2 Wheel sensor Vehicle speed* 2 2010 Pathfinder |