ANALYSIS ON THE ROLE OF ENGINE COOLANT TEMPERATURE SENSOR IN GASOLINE ENGINE

A gasoline motor engine using electronic control system has several sensors and actuators driven by a computer. This paper aims to reveal the role of an engine temperature sensor mounted on a gasoline engine motor. The testing data shows that there is a connectivity between the temperature data obtained from the coolant temperature sensor with the fuel injection time and the exhaust gas emission content.


INTRODUCTION
Electronic control system on a vehicle engine aims to optimize engine performance so that it can save fuel, has bigger power performance and inflicted emission can be pressed.To achieve it, a good synergy between sensor, actuator and its control center are needed.
Sensor roles as a collector of information mounted in the engine.Whereas control center acts as the data receiver which comes from the sensor, and then process it into specified control logic.So that it can produce "value" which then given to actuator.
This actuator acts to realize a desired situation based on the amount of "value" resulted from the control center.

Electronic Fuel Injection (EFI)
Gasoline injection system with more well-known electronic control is called Electronic Fuel Injection (EFI), fuel injection volume is controlled electronically.The basis of this system has been going through many

Hydrocarbon (HC)
The composing of hydrocarbon (HC) emission is influenced by the original components of its fuel, combustion chambers geometry and engine operational parameter.
If HC emission is entering the atmosphere, several of them are carsinogenic sensing elements which can cause cancer.HC (Hydrocarbon) is blackish, and aromatic.This gas occured when the combustion process on the combustion chambers does not work well or excessive fuel supply.The breakdown in ignition system is the major symptom.This gas can cause eyes irritation, nose and throat (ISPA) and eventually causing serious deseases.
Carbon Dioxide (CO2) The higher the CO2 substance in the exaust gas identifies that the more combustion occured inside the engine.
Otherwise, the lower the CO2 level in the exhaust gas shows that the combustion efficiency is not good and in accordance with

Result
The obtained data then undergoes tabulation into Table 1.In Figure 4, it can be seen that there is connectivity tendency between cooling temperature and injection time.The tendency is the more increase the cooling temperature, the shortest the injection time.

Cooling temperature and exhaust gas emission content
The data taken from Table 1 is  In Figure 6, it can be stated that there is a connectivity tendency between cooling temperature and HC content on exhaust gas emission.The occuring tendency is the more increase the cooling temperature, the lower the HC content.

CONCLUSION
The result of this study proves that engine heat detected through coolant temperature sensor has connectivity with injection time.This injection time influences the combustion process where the longer the injection time, the more amount of fuel needed.So that the exhaust gas emission is then influenced as well.Demonstrably, the longer the injection time causes the tendency of exhaust gas emission becoming worse.
the ideal engine heat can be reached sooner.Engine coolant temperature sensor is one of sensors which information becoming the reference as the condition determinant.This conditioning multiplies fuel injection to the combustion chambers.This study is going to expose the role of engine coolant temperature sensor by analyzing the connectivity between the data of engine coolant temperature, time injection, and exhaust gas emission produced by the engine.Vol.2, No.2, December 2017 ISSN 2528-2611, e-ISSN 2528-2700 The beginning of fuel injection into the combustion chambers method started from 1970 up to 1980 where the system of fuel injection into the combustion chambers using carburetor system.This system intermingles the air and the fuel inside the carburetor.Along with exhaust gas emission regulation, air intermingling process between air and fuel experiences an increase on its setting pattern.Starting from the year 1970s, air mingling system and fuel establishes one generation of new setting pattern namely Electronic Fuel Injection (EFI) (TTA: 2010).

Fig
Fig 1. Coolant Temperature Sensor ECT also functions as engine coolant temperature control toward the driver through temperature gauge mounted on instrument panel.Engine coolant temperature sensor is variabel resistance with NTC (Negative Temperature Coeffecient) sensing element which functions to provide information to ECU on engine cooling temperature.By having this sensing element thus: Cooling temperature is low, sensor resistance value is high.Conversely, coolant temperature is high, sensor resistance is low.

Fig 2 .
Fig 2. Graphic of Coolant Temperature Sensor Characteristic Fig 3. Data Collection Scheme

Fig 4 .
Fig 4. Graphic of Cooling Temperature vs Injection time Fig 5. Graphic of Cooling Temperature vs CO Emission

Table 1 .
Testing result on Stand Toyota Avanza Engine