ISC (IDLE SPEED CONTROL) SYSTEM
THE ISC SYSTEM (ROTARY SOLENOID TYPE) INCREASES THE RPM AND PROVIDES IDLINGSTABILITY FOR FAST IDLE-UP WHEN THE
ENGINE IS COLD AND WHEN THE IDLE SPEED HAS DROPPED DUE TO ELECTRICAL lOAD. ETC. THE ECU EVALUATES THE SIGNALS FROM
EACH SENSOR (INPUT SIGNALS (1.2.4 TO 8.11 )). OUTPUTS CURRENT TO TERMINAL ISC1 AND ISC2. AND CONTROLS THE ISC VALVE.
AIC CUT CONTROL SYSTEM
WHEN THE THROTTLE VALVE ANGLE EXCEEDS A PREDETERMINED VALVE. THE AIC IS TURNED OFF FOR A SPECIFIED PERIOD OF TIME TO
IMPROVE ACCELERATION PERFORMANCE.
THE ECU RECIEVES INPUT SIGNALS (5). AND OUTPUTS SIGNALS TO TERMINAL ACT.
FUEL PRESSURE CONTROL SYSTEM
THE FUEL PRESSURE UP SYSTEM CAUSES THE VSV (FOR FUEL PRESSURE UP) TO COME ON FOR HIGH TEMP. STARTS AND FOR ABOUT
120 SECONDS AFTER STARTING IN ORDER TO INCREASE THE FUEL PRESSURE. IMPROVE STARTABLITY AT HIGH TEMPERATURES AND
PROVIDE STABLE IDLING THE ECU EVALUATES THE INPUT SIGNALS FROM EACH SENSOR (1 AND 11) OUTPUTS CURRENT TO
TERMINAL FPU AND CONTROLS THE VSV.
OXYGEN SENSOR HEATER CONTROL SYSTEM
THE OXYGEN HETER CONTROL SYSTEM TURNS THE HEATER TO ON WHEN THE INTAKE AIR VOLUME IS LOW (TEMP. OF EXHAUST EMISSION
LOW). AND WARMS UP THE OXYGEN SENSOR TO I NPROVE DETECTI ON PERFORMANCE OF THE SENSOR. THE ECU EVALUATES THE SIGNALS
FROM EACH SENSOR (INPUT SIGNALS (1.9.10.11)). CURRENT IS OUTPUT TO TERMINAL HT AND CONTROLS THE HEATER.
DIAGNOSIS SYSTEM
WITH THE DIAGNOSIS SYSTEM. WHEN THERE IS A MAlFUNCTIONING IN THE ECU SIGNAL SYSTEM. THE MALFUNCTION SYSTEM IS
RECORDED IN THE MEMORY. THE MALFUNCTIONING SYSTEM CAN THEN BE FOUND BY READING THE DISPLAY (CODE) OF THE CHECK ENGINE
WARNING LIGHT.
FAIL-SAFE SYSTEM
WH~N 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 FA IL -SAFE SYSTEM EITHER CONTROLS THE SYSTEM BY US ING DATA (STANDARD
VALUES) RECORDED IN THE ECU MEMORY OR ~ELSE STOPS THE ENGINE.
