Ignition Coil & Fault
An ignition coil is a key component in a vehicle’s ignition system that converts low voltage from the battery into high voltage to create a spark at the spark plugs. This spark ignites the air-fuel mixture in the engine’s cylinders, allowing combustion to take place.
How an Ignition Coil Works:
1. The car’s battery provides 12V of electricity.
2. The ignition coil transforms this low voltage into a high-voltage charge (usually between 15,000–40,000 volts, sometimes even higher).
3. The high-voltage current is sent to the spark plug, creating a spark.
4. The spark ignites the air-fuel mixture inside the combustion chamber, generating power.
Symptoms of a Bad Ignition Coil:
1. Engine Misfires – The engine stutters or runs unevenly.
2. Hard Starting – Weak or no spark makes the engine difficult to start.
3. Rough Idling & Stalling – The engine vibrates or shuts off unexpectedly.
4. Loss of Power & Poor Acceleration – Reduced power due to incomplete combustion.
5. Decreased Fuel Efficiency – More fuel is burned due to inefficient combustion.
6. Check Engine Light On – A faulty ignition coil may trigger an engine warning.
7. Backfiring or Exhaust Smoke – Unburned fuel exits through the exhaust.
Common Causes of Ignition Coil Failure:
>> Heat & Vibration: Over time, heat and engine vibrations wear down the coil.
>> Oil or Water Contamination: Oil or moisture leaks can damage the coil.
>> Faulty Spark Plugs or Wires: Bad plugs can make the coil work harder and fail sooner.
>> Electrical Problems: Short circuits, bad grounds, or voltage spikes can cause coil failure.
>> Normal Wear & Tear: Coils degrade over time, typically lasting 60,000–100,000 miles.
How to Fix a Bad Ignition Coil:
1) Diagnose with an OBD-II Scanner: Check for error codes like P0351–P0356 (coil circuit issues).
2) Inspect & Test the Coil: Use a multimeter to measure resistance and check for cracks, burns, or leaks.
3) Replace the Faulty Ignition Coil: If damaged, install a new coil (consider replacing all if one fails).
4) Check Spark Plugs & Wires: Worn-out plugs or wires can cause coil failure, so replace them if needed.
5) Address Oil or Water Leaks: Fix any leaks that may be damaging the coil.
Types of Ignition Coil Configurations:
(1) Single Coil: One coil for the entire engine (older vehicles).
(2) Coil Pack: A set of multiple coils for different cylinders.
(3) Coil-on-Plug (COP): One coil per spark plug (modern vehicles).
(4) Distributor Coil: Works with a distributor to send sparks to different cylinders (older ignition systems).