PGM-FI System Description - Injection Control (2013-15)
Fuel injection controls include fuel injection amount control, fuel cut control and fuel pump control. Adopting PGM-FI (programmed-fuel injection) technology enables accurate fuel controls, which contributes to increased engine power and decreased fuel consumption.
Fuel Injection Amount
The fuel injection amount is determined by adding correction values to a basic injection amount. The PCM controls the amount of fuel injection by the length of time the injector is energized.
Fuel Injection Timing
The fuel injection timing is determined by the PCM, which calculates the injection time for each cylinder based on the signals sent from the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor.
CKP Sensor
The CKP sensor is attached to the oil pan. Everytime each of the 58 teeth on the crankshaft pulser plate passes over it, a pulse signal is delivered to the PCM.
CMP Sensor
The camshaft position (CMP) sensor is attached to the cylinder head (front bank). Every time one of the five protrusions of the camshaft pulley passes over it, a pulse signal is delivered.
Fuel Injector
The fuel injector has multiple holes. A nozzle with multiple holes increases the fuel atomization and improves mixing with the surrounding air. When the coil in the injector is energized, the plunger is pulled in. The needle valve, which is integral with the plunger, is pulled also. Then, the injector sprays the fuel whose pressure is controlled by the fuel pressure regulator.
MAF/IAT Sensor
A mass air flow or MAF sensor and an intake air temperature or IAT sensor are installed at the outlet of air cleaner to detect the amount of intake air and the intake air temperature. Within the mass air flow is a hot wire, cold film and IC. As air passes the heated hot wire, the resistance changes as it is cooled by the airflow. This is used to detect the amount of intake air. The control circuit installed in the IC detects the resistance of the hot wire and the cold film so that temperature difference between the hot wire and the cold film is held constant. The intake air quantity is calculated based on the current value and voltage that is input to the PCM. The Intake air temperature or IAT sensor uses a thermistor that changes resistance depending on the intake air temperature. This causes a variable voltage that is sent as an input to the PCM.