ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION — Multiport Fuel Injection (MFI) System
EF & EC-7017prose procedureECM function and Actuator columns are merged (single rowspan) in the source; values are placed on the first row only.
Multiport Fuel Injection (MFI) System
CG10, CGA3
DESCRIPTION — Input/Output Signal Chart
MFI Input/Output Signal Chart
Crankshaft position sensor (POS)
Input Signal to ECMEngine speed and piston position
ECM functionFuel injection & mixture ratio control
ActuatorInjector
Camshaft position sensor (PHASE)
Input Signal to ECMCylinder number
ECM function
Actuator
Mass air flow sensor
Input Signal to ECMAmount of intake air
ECM function
Actuator
Engine coolant temperature sensor
Input Signal to ECMEngine coolant temperature
ECM function
Actuator
Heated oxygen sensor 1 (front)
Input Signal to ECMDensity of oxygen in exhaust gas
ECM function
Actuator
Throttle position sensor
Input Signal to ECMThrottle position; Throttle valve idle position
ECM function
Actuator
PNP switch
Input Signal to ECMGear position
ECM function
Actuator
Vehicle speed sensor
Input Signal to ECMVehicle speed
ECM function
Actuator
Ignition switch
Input Signal to ECMStart signal
ECM function
Actuator
Air conditioner switch
Input Signal to ECMAir conditioner operation
ECM function
Actuator
Electrical load
Input Signal to ECMElectrical load signal
ECM function
Actuator
Battery
Input Signal to ECMBattery voltage
ECM function
Actuator
Power steering oil pressure switch
Input Signal to ECMPower steering operation
ECM function
Actuator
Heated oxygen sensor 2 (rear)
Input Signal to ECMDensity of oxygen in exhaust gas
ECM function
Actuator
Basic Multiport Fuel Injection System
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 camshaft 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 operating conditions as listed below.
<Fuel increase>
- During warm-up
- When starting the engine
- During acceleration
- Hot-engine operation
- High-load, high-speed operation
<Fuel decrease>
- During deceleration
- During high engine speed operation
- During high vehicle speed operation (M/T models)
- Extremely high engine coolant temperature