Home » Automobile engg » Electronic Ignition System: Diagram, Working, Advantages [PDF]

Electronic Ignition System: Diagram, Working, Advantages [PDF]

In this article, you’ll learn what is Electronic Ignition System? Its Diagram, Components, Working, Advantages, and Application are explained in detail.

Also, you can download the free PDF file of this article at the end.

What is Electronic Ignition System?

An electronic ignition system is a type of ignition system that uses a transistor to make an electronic circuit work. A sensor controls this transistor to create an electrical pulse, generating a high voltage spark that can burn the lean mixture and provide a better economy and lower emissions.

The role of the electronic ignition system remains the same as it generates a high voltage spark to ignite the air-fuel mixture to the spark plug. Since sensors are used in the system, it improves reliability and mileage and also reduces emissions.

Electronic ignition systems are widely used in aircraft engines, bikes, motorcycles, and cars because they serve the same purpose as other ignition systems. The advantage of an electronic ignition system is that it is entirely electronically controlled. Delco-Remy tested the first electronic ignition (a cold cathode type) in 1948.

Beyond that, a lot more needs to be understood about this ignition system. So I have briefly explained the electronic ignition system with its components, advantages, and more. let’s get started.

Read Also: How a Distributorless Ignition System works? [PDF]

Why Electronic Ignition System Adopted?

The conventional electro-mechanical ignition system uses a mechanical contact breaker. Although it is simple, it has some limitations, which are as follows:

  1. Contact breakpoints have to handle heavy current, resulting in burns to contact points. Thus it requires servicing and settings from time to time.
  2. Mechanically driven contact breakers have inertial effects. So at high speeds, the make or break of the contact may not be timed accurately.
  3. The coil has less time to build up the current to its maximum value at higher speeds. Thus the strength of the spark can be reduced.

To get rid of these above drawbacks, electronic ignition systems are used in modern automobiles. Unlike electro-mechanical systems, this electronic ignition system performs best in all different conditions and speeds.

These types of ignition systems consist of transistors, capacitors, diodes, and resistors. These act as heavy-duty switches controlling the primary current for the high voltage ignition coil.

Components of Electronic Ignition System

Following are the important components of an electronic ignition system:

  1. Battery
  2. Armature
  3. Ignition switch
  4. Electronic control module (ECU)
  5. Ignition coil
  6. Ignition distributor
  7. Spark plug
Electronic Ignition System Diagram

Checkout: What is a Fuel Filter? Its Working & Types [How To Clean Guide]

#1 Battery

The battery is the primary power source for the ignition system because it transfers the energy to the system when the ignition switch is turned on. The function of a battery is to store charges and release them when needed.

It has two terminals: positive (+) and negative (-). The positive terminal is connected to the ignition switch (key), while the negative terminal is connected to the ground.

#2 Armature

Unlike battery ignition systems with contact breaker points, this is being replaced by an armature in an electronic ignition system. The armature is used to generate the magnetic field in the system.

It consists of a retractor (moving part) with teeth, a vacuum advance, and a pickup coil to capture voltage signals. The ECU receives voltage signals from the armature so that circuits can be made and broken. This accurately determines the timing of the current supply to the distributor’s spark plugs.

#3 Ignition Switch

It’s the power button that turns the system on and off. When the switch is turned on, the current from the battery runs directly to the coil and into the ignition system. Similarly, when the switch is turned off, the current from the battery will be terminated, so even if the engine is cranked, it will not run.

#4 Electronic Control Module (ECU)

It is the essential part of the electronic ignition system in which electronic work starts as it switches the primary current on and off. This is known as the brain or programmed instructions given to the electronic ignition system.

Also called as Control Unit, which automatically monitors and controls the timing and intensity of sparks. It receives the voltage signal from the armature and turns the primary coil on and off. These are kept separately outside the distributor or the vehicle’s electronic control unit box.

#5 Ignition Coil

An ignition coil in the system is beneficial as it helps the spark plug to generate a higher voltage up to 12 V to 20 KV. It uses the electromagnet induction method, which acts as a step-up transformer.

This transformer produces a low flame or high voltage spark for combustion. There are two sets of ignition coil windings: primary winding (outer winding) and secondary winding (inner winding).

#6 Ignition Distributor

Despite the magneto ignition system, electronic ignition systems also have an ignition distributor. This is because, in electronic ignition, only the primary current termination method differs and the rest is the same. It distributes the current to the spark plugs of a multi-cylinder engine.

#7 Spark Plug

The spark plug generates the spark inside the cylinder by using the high voltage ignition coil to ignite the fuel-air mixture. It usually works by using the gap between two conductors. One is the spark electrode which is positively charged, and the other is the ground which is negatively charged.

Read Also: What is Camshaft? Parts, Function, Application [Explained]

Working of Electronic Ignition System

The above figure shows you a simplified diagram of an electronic ignition system. In the electronic ignition system, a timer is employed in the distributor of the electronic ignition system.

The timer sends the electrical pulses to an electric control unit (ECU) which switches off the flow of current to the primary winding. As a result, a high voltage is induced in the secondary winding which is then distributed to the spark plugs as in the case of a breaker point ignition system.

The electronic control unit later switches on the flow of current to the primary circuit so that the primary circuit can be built up for the next cycle. The timer may be a pulse generator or Hall effect sensor.

Other than this, the electronic ignition system works similarly to a conventional type. The other few types of commonly used timers in electronic ignition are pulse generator, Hall effect switch, Optical switch, and Capacitor Discharge method.


  1. It has no moving parts. Solid-state electronics control all operations of the ignition system.
  2. The system does not rely on a range of factors to be mechanically timed by the system for the timing of spark plug activation.
  3. Electronic ignition systems provide better environmental benefits than mechanically timed ignition.
  4. Since the system has fewer moving parts, it increases its efficiency.
  5. The use of this system will increase fuel efficiency as well as generate fewer emissions.

Don’t Miss Out: 25 Car Dashboard Warning Lights and Indicators [Explained]


Despite the advantages of electronic ignition systems, there is still one drawback. The main disadvantage of electronic ignition systems is that not all vehicles can tolerate this type of ignition system.


Electronic ignition is mostly used in modern supercars like Audi A4, Mahindra XUV-500, etc., and bikes like KTM Duke 390 cc, Ducati Super Sports, etc., to meet the need for high reliability and performance. It is also used in aircraft engines due to its superior reliability and low maintenance.

Closing It Up

Now, I hope I’ve covered everything you were looking for in this article. If you still have any doubts or questions regarding this topic, leave a comment below I’ll definitely reply. If you liked it, then share this with your friends.

Want free PDFs direct to your inbox? Then subscribe to our newsletter.

Download PDF of this article:

You might like to read more in our blog:

  1. Types of Fuel Pump and Its Working Principle
  2. How Does Camshaft Position Sensor Work?
  3. Symptoms of a Bad Crankshaft Position Sensor
About Yousef

He is a mechanical engineering student, he likes to write about engineering stuff and he is really interested in learning about new technology in machines.

4 thoughts on “Electronic Ignition System: Diagram, Working, Advantages [PDF]”

  1. I wanna say thanks because still I’m learning different things..I’m so interesting…thanks for your posts


Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.