Engine control unit (ECU)

Engine control unit or Electronics Control unit is an electronic device that read the signals coming from various sensors which are placed at different components of car and uses this information to direct those components what to do. It’s more like a brain of vehicle. An ECU is basically made up of hardware and software.ECU is like a computer that communicates with engine and determines almost everything. The primary objective of ECU is to make sure that things are going well in the engine. After receiving the signals from various sensors, its ECU’s responsibility to provide necessary instruction what to do and how to operate for running engine perfectly.ECU directly affects the performance of engine as it helps to enhance the performance of engine.

ECU

Types of ECU

The types of ECU depends upon on what it is being used for and they are differentiated as below

Engine Control Module (ECM)

ECM is also knows aas Engine management system in an IC engine that controls various function like speed control, ignition timing, fuel injection. All these functions are performed after receiving data from various sensors kept at various places.

EBCM – Electronic Brake control module.

This is an ECU that is used in the anti-lock braking system of a car. They were introduced to improve vehicle braking irrespective of the road and its conditions. It is getting more popular nowadays.
The EBCM regulates the braking systems on the basis of signal that it receives from different sensors

1. The Brake: It gives the status of the brake pedal.

2. The four wheel drive: It gives the status whether the vehicle is in the four wheel drive mode.

3. The Ignition: It registers if the ignition key is in place and if engine is running or not.

4. Vehicle Speed: It gives information about the speed of the vehicle.

5. Wheel speed: It gives the information about speed of all wheels of a vehicle

Powertrain control module (PCM)

PCM is an ECU that monitors and controls charging and Automatic Transmission,  speed control, A/C,. The inputs that are fed to the PCM are from:

1. throttle position sensor,
2. output shaft speed sensor,
3. engine speed sensor (CKP)
4. cruise control switches
5. ignition
6. governor pressure sensor.
7. vehicle speed sensor
8. brake switch
9. overdrive switch

Vehicle control module(VCM)

VCM is an ECU that takes care of systems like:

1. Adaptive Cruise control (ACC) systems
2. Electronic Power steering (EPS) systems
3. Electronic Stability Control (ESC) systems
4. Airbag control system (ACS) systems.

The VCM is generally installed in the middle of the car between  the engine compartment and the passenger. They are connected to various kinds of sensors to control various systems in the car. They take information from different sensors to perform better in above systems.

Body control module (BCM)

BCM is an ECU that takes care of wiper control, seating control unit, power windows and door locks in different vehicle.

There are few disadvantages of ECU. As it has complex structure, it is hard to repair. But the feature it gives makes it worth taking risk to have it in your vehicle

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Disc Brake and Drum Brake

Disc brake

Disc brake is type of brake which is very common in modern day vehicle which used the friction to bring down the motion of wheel. The main components of disc brake are calipers, rotor and brake pads. The main principle of disc brake is calipers squeezes brake pads against rotor, which produces friction and it slows down the motion. It was first used by Jaguar team in a racing competition, which they won by competing with others using brake drum.

Disc Brake and its main components

Generally, disc brake is always used on front wheels of vehicle. One of the main reason for this is weight is always transferred on front wheels when we apply brake. Since, disc brake is more efficient and it takes less reaction time, disc brake is always preferred. This kind of brake also uses brake fluid to transfer force from brake pedal to calipers in the brake system. We should always check brake pads condition while changing Motor oil (Engine oil) after vehicle runs certain distance. Due to more open space, brake pads and rotor loses heat more easily and this brake became more popular because of this advantage.

Brake pads

Brake Pads

Brake pad is the most important component of disc brake because it squeezes against rotor to change kinetic energy of wheel into thermal energy with the help of friction. It is made up of metallic materials, semi metallic material or from ceramics. At first asbestos was used to make brake pads but, because of its health hazard it was made obsolete WVA numbering system is generally used all around the world for cataloging the brake pads

Rotor

Rotor

Rotor which is also known as disc can be easily seen on wheel. Rotor is squeezed by brake pads to stop the vehicle. There are various types of rotor used in vehicle nowadays. Some of them are plain, drilled, slotted and drilled and slotted. Drilled and slotted are the types of rotor which dissipates the heat quickly.

Drum Brake

Drum brakes was more popular before disc brake was invented. The main principle of drum brake is it used brake shoes against brake drum to produce friction which slows down the motion of vehicle. The main advantage of brake drum is it easily fits emergency brakes in it which is why it is kept at rear wheels. It is also less expensive than disc brake. The main components of drum brake are brake lining, piston, wheel cylinder, emergency brake lever and drum.

Drum Brake

 The main advantages of drum brakes are it is less expensive and we can easily fit emergency brake system in it. The disadvantage of drum brake is  it takes lot of time to dissipate heat which is produced by friction in it. It is because there is less open space and all mechanism takes place inside drum so in some cases people generally pour water on drum brake so that it could dissipate heat easily.

Brake Shoes

Brake Shoes

Brake shoes are made of 2 pieces of steel which are welded together. The friction material may be attached with adhesive or riveted on it. There is web and it contains holes which are used for return spring, parking brake lining and self-adjusting component. Every brake assembly has two shoes one is primary and another is secondary. Primary, is located toward the front and is positioned differently from secondary shoe 

As we have seen the features of disc brake and drum brake. Now it is much easier to know why disc brake is more popular. 

Tags: Disc Brake, Drum Brake, Brake Pads, Brake shoe

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Two Stroke Engine, Four Stroke Engine and Difference between 2stroke and 4stroke

Two stroke engine

Two stroke engine is a kind of internal combustion engine which completes power cycle in 2 stroke. That is up and down movement of a piston during one complete revolution of crankshaft. First two stroke engine was patented by Dugald Clerk in the year 1881. Since then this type of engine was used. Generally spark ignition two stroke engine is used to carry lightweight and compression ignition is used to carry heavy goods.

Two stroke cycle operation

The main principle of two stroke engine is inlet and compression stroke takes place in half rotation of crank shaft and power and exhaust stroke takes place in another half stroke of crankshaft. 

These types of engine have high power to weight ratio. Since, the power stroke is achieved in every revolution, it produces constant power .This is the reason why this type of engine is used in chainsaw. Also, it is less expensive and easier to construct. There is no valve in two stroke engine like in four stroke engine. In two stroke engine , we have to mix engine oil with fuel as there is no chamber to hold engine oil. The main disadvantage of two stroke engine is engine parts wear fast as there is lack of proper lubricating system and it produces pollution as the engine oil is burned with fuel in combustion chamber.

Four Stroke Engine

Four stroke engine is also an IC engine in which 4 different strokes takes place in a complete cycle. Unlike two stroke engine, four stroke engine uses valves and it has complex structure. 

Four stroke cycle operation

The inlet stroke takes place when piston moves from top to bottom. The compression stroke takes place when piston moves from bottom dead center (lowest point to which piston can travel) to top dead center (highest point to which piston can travel). Similarly, when piston travels from TDC to BDC, the power stroke is completed and piston moves from bottom to top in exhaust stroke. Four stroke engine last longer than  two stroke engine as there is provision of lubricating engine parts thus reducing wear of parts. It produces more power making it suitable to carry heavy goods. It produces less pollution as well. The main disadvantage of four stroke engine is it produce power once in two rotation of crankshaft

Difference between 2stroke and 4stroke

1. The general difference between 2 stroke and 4 stroke are
2. Two stroke produces power in every rotation of crankshaft whereas four stroke produces power in every 2 rotation of crankshaft.
3. Two stroke engine wear more fast than four stroke engine because of lack of proper lubricating system but there is a system for lubrication in four stroke engine.
4. Two stroke engine are lighter and easy to construct but Four stroke engine is heavier and complex to construct with valves
5. Two stroke engine produces more pollution as engine oil gets burned with fuel which doesn’t happen in 4 stroke engine

From the above description it is easier to choose between two stroke and four stroke engine with proper reason 

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Motor oil,its grade and how to change motor oil quickly

Motor Oil

Motor oil which is also known as engine oil or engine lubricant is mainly used for lubrication of engine and it also helps to reduce wear in moving part. Motor oil also takes away heat from moving parts and improve sealing. Motor oils are derived from non-petroleum-synthesized and petroleum based chemical compounds. Generally there are four types of motor oil:-

1. Synthetic motor oil:- It is the best kind of motor oil which is obtained by synthesis of different ingredients. It provide better cleansing quality and better protection at startup.
2. Synthetic blend motor oil:- It is the mixture of conventional base and Synthetic oil which is used for vehicle with high RPM's and it has better properties at low temperature.
3. High Mileage motor oil:- It is specially made for older vehicle or vehicle with high mileage. It provide better sealing in combustion chamber.
4. Conventional Motor oil:- It is the mixture of conventional base oil with chemical additives.nowadays, almost every vehicle use synthetic oil so read owner manual before reading deciding about motor oil.

Different grade of motor oil

Society of automotive engineers (SAE) has developed a rating system of motor oil by its viscosity.Generally, we see SAE 5W-30 or SAE 10W-30 written on engine oil.Here "W" is winter. In 5W-30 , 5 is the cold temperature viscosity rating and 30 is the high temperature viscosity rating.At low temperature, oil has low viscosity and it is thick at that temperature and at high temperature , it gets thinner.we should always check owner manual to decide the motor oil.

How to change engine oil quickly

When it shows engine oil signal glowing in screen, you should realize its time to change engine oil.changing engine oil is not very difficult task. you can easily perform if you follow following steps

1. If engine is cold, start foe few minutes to warm the oil. If it is hot, wait for few minutes to avoid getting burned
2. Place the jack in front side of vehicle to raise the front part
3. locate the drain plug and remove it
   
4. place a oil drain pan under drain plug to collect old oil and also locate oil filter as oil must be changed as well when oil is replaced and use oil filter wrench to remove it 
   
5. Now install and tighten the drain plug and oil filter.Now remove the cap of engine oil which is under hood and pour new engine oil 
   
6. check engine oil leakage by getting under the vehicle and check dip stick to check level of engine 
   

By following these few steps,we can easily change engine oil

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Brake system and procedure to change brake fluid

Brake system

Brake system is a group of electronic, mechanical and hydraulic activated  devices which generally uses friction to stop vehicle.The main components of brake are Brake Booster, Brake Pedal ,Brake Fluid, Brake Pads, Drum Brakes, Rotor, Master Cylinder,Hydraulic Lines,Brake Fluid, Hydraulic Calipers, Drum, Brake Shoes,Wheel Cylinder.

 The main principle of brake system is as we press brake pedal,the brake pedal is connected to brake booster by lever and rods.brake booster multiplies and transfers the force produced from brake pedal to master cylinder and this force transferred from brake booster is used to pressure brake fluid through hydraulic lines to 4 brakes mounted on wheels of vehicle.these brake fluid at each wheel  use hydraulic pressure to create friction and stop the motion of vehicle

How to change brake fluid and perform brake bleeding method

There are different type of brake fluid available in market with different grade.always check owner manual to know the suitable grade of brake fluid for your vehicle

Generally, the brake fluid with grade DOT 3,DOT 4,Dot 5.1  are commonly used.using wrong grade brake fluid can effect efficiency.

Brake fluid can be changed easily can performing following three simple steps:-

1. Remove the old,dirty brake fluid from the master cylinder by using turkey baster
   
2. Use  a lint-free cloth to wipe out fluid in reservoir only if u can get in there
3. Pour new brake fluid into the reservoir until it reaches "max" line 
     

brake bleeding

Bleeding operation is performed to take out the air from brake pipes so that there will be smooth flow of brake fluid. So, make sure the bleeder valves can be loosened.You will need wrench that fits the bleeder bolt.Loosen the bolts, but leave them closed.

Get a piece of clear plastic tube. Put one end of the tube over the brake bleeder bolt and other end of the tube into a small, clear bottle with clean brake fluid in it. so that air won't sucked back into the brake cylinder or caliper. 

Fill the master cylinder with new brake fluid and put the cover back on the reservoir. Fluid will come out of  reservoir when pedal is release. Continue this till clean brake fluid comes out of bleeder valve.

In this way the brake fluid can be changed and bleeding brake operation can be performed to better performance of brake system

Tags: automobiles brake system, change brake fluid,bleeding brake, 

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