Engine Control
This system utilizes an Engine Control Module and maintains overall control of the Engine, transmission and so on. An outline of the Engine Control is explained here.1. INPUT SIGNALS
1. Water Temp. signal system
The Engine coolant Temp. Sensor detects the Engine Coolant Temp. and has a built-in thermistor with a resistance which varies according to the water temp.. Thus the water temp. Is input in the form of a control signal to TERMINAL THW of the Engine Control Module.
2. Intake Air Temp. Signal System
The intake air temp. sensor is detects the intake air temp., which is input as a control signal to TERMINAL THA of the Engine Control Module.
3. Oxygen Density Signal System
The Oxygen density in the Exhaust Emissions is detected and input as a control signal from oxygen sensor and heated oxygen sensor TERMINAL OX1 and OX2 of the Engine Control Module.
4. RPM Signal
Crankshaft position is detected by crankshaft position sensor. Crankshaft position is input as a control signal to TERMINAL NE of the Engine Control Module, and Engine RPM is input to TERMINAL G2 of the Engine Control Module,
5. Throttle Position Signal System
The Throttle position sensor detects the Throttle Valve Opening angle, which is input as a control signal to TERMINAL VTA of the Engine Control Module, or when the valve is fully closed.
6. Vehicle Speed Signal System
The speed meter inside the Combination Meter sends a vehicle speed signal to TERMINAL SPD of the Engine Control Module as a control signal.
7. Neutral Position Signal System (A/T)
The Park/Neutral Position SW (Neutral Start SW) detects whether the shift position is in neutral and parking or not, and inputs a control signal to TERMINAL NSW of the Engine Control Module.
8. A/C SW Signal System
The A/C Amplifier inputs the A/C operations to TERMINAL AC1 of the Engine Control Module as a control signal.
9. Battery Signal System
Voltage is constantly applied to TERMINAL BATT of the Engine Control Module. When the Ignition SW is turned to ON, Voltage for ECU operation is applied via the EFI main relay to TERMINAL +B of the Engine Control Module.
10. Intake Air Volume Signal System
Intake Air Volume is detected by the manifold absolute pressure sensor and is input as a control signal to TERMINAL PIN of the Engine Control Module.
11. STA Signal System
To confirm that the Engine is cranking, the voltage applied to the starter motor during cranking is detected and is input as a control signal to TERMINAL STA of the Engine Control Module.
12. Electrical Load Signal System
The signal when systems such as the Rear Window Defogger, Headlights, etc. Which cause a high electrical burden are ON is input to TERMINAL ELS1, ELS2 as a control signal.
2. CONTROL SYSTEM
^ SFI system Monitors the Engine Revolutions through the signals each sensor (Input Signals (1) to (12)) inputs to the Engine Control Module. Based on this data and the program memorized in the Engine Control Module (ECU), the most appropriate fuel Injection timing is decided and current is output to TERMINALS #10, #20, #30 and #40 of the Engine Control Module, causing the Injectors to operate it (To Inject Fuel). It is this system which, through the work of the Engine Control Module, finely controls fuel Injection in response to driving conditions.
During Engine Cranking (Signal Input To TERMINAL STA) or for Approx. 2 Seconds after NE signal input, Engine Control Module operation energizes (Point Closed) the fuel pump circuit inside the circuit opening relay, causing the fuel pump to operate.
^ ESI System
The EI system Monitors the Engine Revolutions using the signals (Input Signals (1, 4, 5, 10, 11)) input to the Engine Control Module from each sensor. Based on this data and the program memorized in the Engine Control Module, the most appropr1ate Ignition timing is decided and current is output to TERMINAL IGT of the ECU. This output controls the Igniter to produce the most appropriate Ignition timing for the driving conditions.
^ Idle Air Control System
The Idle Air Control system increases Engine Speed and provides idling stability for fast idle-up when the Engine is cold and when the idle speed has dropped due to electrical load, etc. The Engine Control Module evaluates the signals from each sensor (Input Signals (1, 4 to 8, 11, 12)), outputs current to TERMINAL RSC and RSO, and controls the Idle Air Control valve.
^ EGR Control System
The EGR cut control system controls the VSV (EGR System) by evaluating the signals from each sensor input to the Engine Control Module (Input signals (1,4,10)) and by sending output to TERMINAL EGR of the Engine Control Module.
^ A/C Cut Control System
When the vehicle suddenly accelerates from low Engine speed, this system cuts off Air conditioner operation for a fixed period of time in response to the vehicle speed and Throttle valve opening angle in order to maintain acceleration performance.
The Engine Control Module receives input signals (5, 6), and outputs signals to TERMINAL ACT.
3. DIAGNOSIS SYSTEM
With the diagnosis system, when there is a malfunctioning in the Engine Control Module signal system, the malfunction system is recorded in the memory. The malfunctioning system can then be found by reading the display (code) of the malfunction indicator lamp.
4. FAIL-SAFE SYSTEM
When a malfunction occurs in any system, if there is a possibility of Engine Trouble being caused by continued control based on the signals from that system, the Fail-Safe system either controls the system by using data (Standard Values) recorded in the Engine Control Module memory or else stops the Engine.