Skip the auto shop - Our mechanics make house calls

Q: How Do the Three Types of Vehicle Ignition Systems Differ From Each Other?

asked by on

How do the three types of vehicle ignition systems differ from each other?

A: I’m going to commit the unpardonable sin an...

I’m going to commit the unpardonable sin and "assume" that the three types of ignition systems being referred to are the points, coil pack, and coil-on-plug. There are actually four types of vehicle ignition systems.

Points-type ignition systems that were used on vehicles up through the early 1980’s are mechanical and can be adjusted. This system used a single ignition coil to spark all of the cylinders. The typical ignition tune-up required the replacement of the contact points, condenser, spark plugs, distributor cap, rotor, and possibly the spark plug wires. The points had to be adjusted for proper air gap when open to allow the ignition system to work as designed.

The first type of electronic ignition still used a distributor cap, rotor, and spark plug wires. This system replaced the contact points and condenser with a trigger wheel, called a reluctor, and an electronic pickup. A small ignition control module was used to control the spark timing.

Coil pack ignition systems are fully electronic and, as such, have no distributor, rotor, contact points, or condenser. This system uses a crankshaft position sensor and a camshaft position sensor. Coil pack ignitions have either two or three ignition coils mounted together in a single assembly. Spark plug wires are attached to the coil towers and are routed to their respective spark plug.

Coil-on-plug ignition systems are also fully electronic and, likewise, use a crankshaft position sensor and a camshaft position sensor. Coil-on-plug systems use a single ignition coil for each spark plug. This system does not use spark plug wires because the ignition coils sit directly on top of its respective spark plug.

Coil-on-plug ignition systems have a modified cousin. On vehicles that have two spark plugs per cylinder, you will have an ignition coil sitting on top of one plug while a second coil is mounted nearby and is connected to its spark plug with a short plug wire.

Whatever type of ignition system your car has, a professional technician can help you out with almost any spark related issue. They can also replace your spark plugs if necessary and at your own convenience.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Have a 3.8 and I changed the spark control module and the code keeps coming up 1993 Pontiac Bonneville

Hello - regarding your ignition system problem - it sounds like replacing the spark control module wasn't the correct "fix". Without knowing what problem code was set, it's hard to know what the correct response should be. If you can...

Q: Motor will not start up right away, takes a while

The cranking without starting is caused by the crankshaft position sensor intermittent open circuit not giving a code in the engine control module continuously. This can make it hard to diagnose. Nissan has a recall 07v527000 dated 11/15/2007 where the...

Q: ignition control module keeps failing

This could be either the ignition control module or the ECM which gives direction to the ignition control module. I would start by checking the power supply to the ignition control module to see if it is receiving any power...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.