Moderate⏱ 30 min10 steps·Original on iFixit ↗

Hyundai HB-20 - ignition coil replacement

HB20 ignition coil replacement procedure.

Attention! Never remove the ignition coil or bring your hand close to the coil while the engine is running! Danger of fatal shock! Always remove the key from the car's ignition before carrying out any maintenance.

Tools (2)

Chave de boca 10 mm buy ↗
Chave de cachimbo 10 mm buy ↗

Step-by-step instructions

Detecting the problem

One of the engine failure problems can be caused by a defect in one of the four ignition coils. There is one coil for each cylinder. They are mounted on the cylinder spark plugs.
These coils generate high voltage at the right time to ignite the fuel under pressure in the cylinder.
If the coil fails, the car loses power, the engine speed fluctuates and causes vibrations when one of the coils does not burn fuel.
The engine fault lamp comes on when one of the cylinders misfires.

Using an OBD Scanner

To capture engine information and fault indications, you will need a Bluetooth OBD interface and a Car OBD Scanner app. In my case, I used Car Scanner ELM OBD2 (Google Play store for Android apps).
Connect the Bluetooth OBD interface to the OBD connector located at the bottom of the dashboard, to the left of the car's steering wheel. See the second and third images.

Car Scanner OBD App

Use an Android smartphone or tablet to install the Car Scanner OBD app. Once installed, open the application
In my case, I used Car Scanner ELM OBD2 (Google Play store for Android apps).
Activate the Bluetooth connection on your smartphone or tablet. And connect to the Bluetooth OBD interface on the application screen.

Checking the fault code

In the Car Scanner ELM OBD2 application, select Fault Codes (DTC) on the main screen and search for the defect. The defect in my car was due to a failure in the Cylinder 2 ignition coil.
Fault P0302 - Cylinder 2 misfired detected, that is, cylinder 2 has failed.

Defective ignition coil

This is a disassembled and defective ignition coil. It receives low voltage pulses through the connector at the top and generates high voltage pulses on the spark plug.
Ignition Coil HB20 1.6 Original Yura code 27301-2B010
See in the second image, a small crack. Through this crack, the high-voltage current is discharged to the engine chassis and not to the spark plug. This is why the cylinder fails to ignite the fuel under pressure.
Attention! Never remove this coil with the engine running! Danger of fatal shock! Always remove the key from the car's ignition before carrying out any maintenance.

Removing the engine top cover

Wait for the engine to cool down. If the engine is hot, it could burn your hand.
The engine top cover must be removed. It is secured with four 10 mm screws. Use a wrench to unlock the screws. And then loosen the screws with a socket wrench.
After removing the screws, push the cover to the right to remove it. Do not force the hoses above the cover.

Removing the ignition coil

Cylinder count is from left to right, as in the image.
Attention! Never remove this coil with the engine running! Danger of fatal shock! Always remove the key from the car's ignition before carrying out any maintenance.
Before removing the coil, you must disconnect the top connector. Pull the gray connector latch to the right to unlock it. See the second image. Once unlocked, you can disconnect it by pulling it carefully.
The ignition coil is held in the engine block by just this 10 mm bolt. See the third image. You can unlock the bolt with a wrench. And then remove it with a socket wrench.

Spark plug and connector inspection

With the ignition coil removed, check if there is any dirt inside the engine, on the spark plug. Clean it if necessary. Also check the good condition of the connector.

Installing the new ignition coil

Insert the new ignition coil into place. To facilitate assembly, fit the connector to the coil first. Screw it in with the socket wrench. After everything is assembled, press the gray connector latch. Make sure everything is securely fastened.
Carefully fit the top cover, inserting it from right to left. Insert the four cover screws and tighten them with the socket wrench.

Verifying engine operation

After starting the engine, the engine failure indication on the dashboard may go off after moving the car. Or if you want, there is an option in the application to delete this indicator.
The engine may take a few minutes to stabilize with the new coil installed.
With the new coil, the engine should maintain rotation and work without vibrations, as in normal use. Engine power must be restored.

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