What Is an Ignition Coil Also Known As?

An ignition coil is also known as a “spark coil.” It’s the high-voltage induction component in gasoline engines that steps up the vehicle’s low battery voltage to the tens of thousands of volts needed to fire the spark plugs. Depending on design and region, you may hear additional terms that describe either the same device or closely related configurations.

Common alternate names and what they mean

Automotive and small-engine communities use several overlapping terms for ignition coils. Some are true synonyms, while others refer to specific packaging or systems that incorporate one or more coils.

• Spark coil — The standard synonym for ignition coil in automotive and engineering references.
• HT coil (high-tension coil) — Common in British and Commonwealth usage; “high tension” denotes high voltage.
• Coil pack — A module containing multiple ignition coils (often for waste-spark systems); sometimes used colloquially to mean an ignition coil, but technically a multi-coil assembly.
• Ignition coil pack — Parts-catalog phrasing for the multi-coil module.
• Coil-on-plug (COP) coil — A single-cylinder ignition coil mounted directly on the spark plug; describes a form factor rather than a different fundamental device.
• Induction coil — The broader electromagnetic device category; an ignition coil is a specialized induction coil designed for engine ignition.
• Pencil coil — Informal term (common in European parts catalogs) for slender COP-style coils.

While “spark coil” is the most direct synonym, terms like “coil pack” and “COP coil” convey how the coil is packaged and deployed on an engine rather than naming a different technology.

Why the terminology varies

Language followed the technology. Older distributor-based systems used a single coil feeding all cylinders, so “ignition coil” or “spark coil” was universal. As engines moved to waste-spark coil packs and then to coil-on-plug designs, everyday usage expanded to include module-level terms (“coil pack”) and mounting descriptions (“COP”). Regional conventions also play a role: “HT” for high voltage is entrenched in UK/Commmonwealth contexts, while North American sources typically say “high voltage” or simply “ignition coil.”

How an ignition (spark) coil works

The ignition coil is a transformer-like device with primary and secondary windings around an iron core. The engine control module (or earlier, mechanical points) rapidly switches current through the primary winding. When the current collapses, the changing magnetic field induces a high voltage in the secondary winding—often 20–40 kV—enough to arc across the spark plug gap and ignite the air-fuel mixture. Modern systems use solid-state drivers and may integrate the driver circuitry into the coil body (especially in COP designs).

Where you’ll see the names in practice

Documentation, diagnostics, and parts catalogs each favor slightly different terms, which can be useful when troubleshooting or ordering replacements.

• Repair manuals and service bulletins: Typically use “ignition coil” as the formal component name; configuration (single, coil pack, COP) is specified as needed.
• Diagnostics: OBD-II fault codes P0350–P0362 reference ignition coil primary/secondary circuit issues; cylinder-specific codes map to individual coils in COP systems.
• Parts catalogs: You’ll find entries under “ignition coil,” “coil pack,” “COP,” or “pencil coil,” depending on the vehicle and market.

Knowing these variants helps match terminology across manuals, scan tools, and parts listings, avoiding confusion when servicing different ignition architectures.

Summary

An ignition coil is also known as a spark coil. In everyday and technical contexts you may also encounter HT coil, coil pack (multi-coil module), coil-on-plug (COP) coil, and the broader term induction coil. These names reflect either true synonyms or specific packaging and deployment of the same fundamental high-voltage ignition component.

Are spark plugs and ignition coils the same?

No, spark plugs and ignition coils are not the same; they are distinct, but interdependent components of a vehicle’s ignition system, where the ignition coil transforms the battery’s low voltage into high voltage to power the spark plug, which then ignites the fuel-air mixture in the engine’s combustion chamber. A failure in one can lead to issues in the other, causing engine misfires, poor performance, and a lit check engine light.
 
What is an Ignition Coil?

• An ignition coil is a transformer that steps up the car’s 12-volt battery power to the thousands of volts needed to create a spark. 
• It creates a powerful magnetic field that, when the circuit is broken, generates a high-voltage current. 
• This high-voltage electricity is then sent to the spark plug. 

This video explains how ignition coils work and how they are different from spark plugs: 59sNGK Spark Plugs USAYouTube · Jul 27, 2021
What is a Spark Plug? 

• The spark plug is the component that actually creates the spark.
• It’s designed to fit into the engine’s cylinder head, with its electrode tip positioned to produce a spark that ignites the fuel-air mixture at the correct time.

This video explains the function of a spark plug: 55s1A Auto: Repair Tips & Secrets Only Mechanics KnowYouTube · Sep 10, 2022
How They Work Together

1. The ignition system sends power to the ignition coil. 
2. The coil transforms this into a high-voltage pulse. 
3. This high voltage travels to the spark plug. 
4. The spark plug uses the electricity to generate a spark across its electrodes, which ignites the fuel in the cylinder. 

Symptoms of a Problem 

• Malfunctioning Ignition Coil: Opens in new tabEngine misfiring, reduced power, poor fuel economy, difficulty starting, and a glowing check engine light.
• Malfunctioning Spark Plug: Opens in new tabDifficulty starting, engine misfiring, decreased fuel economy, knocking noises, and the check engine light.

This video demonstrates how to determine if the spark plug or the ignition coil is the problem: 32sWay of the WrenchYouTube · May 19, 2020

How much should it cost to replace an ignition coil?

An ignition coil replacement generally costs between $230 and $330, but this can vary significantly based on the vehicle’s make and model, the specific type of ignition coil (e.g., conventional vs. coil-on-plug), and whether it’s a DIY job or professional service. The total cost includes the price of the part itself, which can range from about $50 to $600, and labor costs, which often range from $75 to $150 per hour.
 
Factors influencing the cost:

• Vehicle’s Year, Make, and Model: The type of ignition coil and its complexity varies, impacting the price of the part. 
• Type of Ignition Coil: Conventional coils are less expensive than coil-on-plug (COP) or distributorless ignition system (DIS) coils. 
• Parts Quality: Using a cheap, aftermarket part may be less expensive upfront but could fail sooner than an OEM (Original Equipment Manufacturer) part, according to this Reddit thread. 
• DIY vs. Professional Service: Doing the repair yourself can save on labor costs, but you’ll need the right tools and technical knowledge. 
• Location: Labor rates can vary depending on the shop and your geographic location. 

What to expect in a repair estimate:

• Parts: The ignition coil itself, which can range from $50 to over $600, depending on the model. 
• Labor: The cost for the mechanic’s time, typically charged by the hour, can vary widely. 
• Taxes and Fees: These are usually added to the final bill and are not included in the estimate. 

What are the three types of ignition coils?

Types of Ignition Coils

• Distributor Ignition Coils. With a distributor ignition coil, the ignition coil generates a high-voltage pulse.
• Block Ignition Coils. A block ignition coil contains multiple ignition coils.
• Pencil Coils.
• Ignition Coil Systems (“rails”)

What is another name for the ignition coil?

Another name for an ignition coil is a spark coil or induction coil, though a coil pack refers to a module of multiple coils found in newer vehicles. Other terms include high-tension coil, ignition transformer, distributor coil, and in some cases, a magneto coil. 
Here are some common alternative names and related terms for an ignition coil:

• Spark coil: Opens in new tabA direct synonym, emphasizing its role in creating a spark. 
• Induction coil: Opens in new tabA broader term describing the device’s function of transforming low-voltage current into high-voltage current through electromagnetic induction. 
• Coil pack: Opens in new tabThis term refers to a housing that contains multiple individual ignition coils, common in distributor-less ignition systems. 
• High-tension coil: Opens in new tabAnother name highlighting its function of producing high-voltage (high-tension) current. 
• Ignition transformer: Opens in new tabSimilar to an induction coil, this term emphasizes its transformer-like function within the ignition system. 
• Magneto coil: Opens in new tabWhile sometimes used as a synonym for older or specific types of coils, it can also refer to the entire magneto ignition system.