A defective ignition coil will cause a misfire trouble code and a misfire condition on the 2002, 2003, 2004, or 2005 2.4L Honda CR-V.
The cool thing is that testing them is not hard and in this tutorial, I'll explain how to do it. You'll be able to find out if you have a defective ignition coil on your hands or not.
Contents of this tutorial at a quick glance:
You can find this tutorial in Spanish here: Cómo Probar Las Bobinas De Encendido (2002-2005 2.4L Honda CR-V) (at: autotecnico-online.com).
Symptoms Of A Bad Ignition Coil
Your 2.4L Honda CR-V is equipped with four ignition coils. These are the ones responsible for creating and delivering spark to their respective engine cylinders. So, when one of these bad boys fail, your Honda CR-V's 2.4L engine is going to misfire.
The most common type of problem that you're gonna' see when one of them fails, on your 2.4L Honda CR-V, is the check engine light lit up by a misfire trouble code.
You're gonna' see one of the following trouble codes:
- P0300: Random Cylinder Misfire.
- P0301: Cylinder #1 Misfire.
- P0302: Cylinder #2 Misfire.
- P0303: Cylinder #3 Misfire.
- P0304: Cylinder #4 Misfire.
You'll also see one or more of the following symptoms:
- Lack of power when accelerating the engine under load.
- Bad gas mileage.
- Rough idle.
TEST 1: Checking For Spark
When an ignition coil fails, it'll simply stop creating spark. This means that we can find out if an ignition coil is defective (or not) by simply testing it for spark with a spark tester.
So for our first test we're gonna' make sure that all four ignition coils are firing spark.
Since testing each ignition coil is a very simple process, I suggest that you test all four of them even if you have a specific cylinder misfire trouble code.
NOTE: To get the most accurate test result, you need to use a dedicated spark tester. The cool thing about a spark tester is that it is not an expensive tool. The spark tester I recommend is the HEI Spark Tester and you buy it here: OTC 6589 Electronic Ignition Spark Tester.
Let's get testing:
Remove the ignition coil from its place on the valve cover.
Connect an HEI spark tester to the ignition coil.
Ground the HEI spark tester with a battery jump start cable directly on the battery negative (-) terminal.
Have a helper crank the engine while you observe the spark tester.
The spark tester should spark if the ignition coil is good.
Test the other 3 ignition coils for spark.
Let's see what your test results mean:
CASE 1: All ignition coils sparked. This is the correct and expected test result and tells you that the ignition coils are OK.
If your 2.4L Honda CR-V is misfiring, then this test result has eliminated the ignition coils as the source of the misfire problem. There's a good chance that the misfire is caused by low engine compression or a defective fuel injector.
I recommend that you continue your misfire diagnostic by taking a look at this tutorial: How To Test Misfire Codes (Honda 2.4L) (at: troubleshootmyvehicle.com).
CASE 2: An ignition coil DID NOT spark. This test result usually means that the COP ignition coil is defective but there's one more thing that you need to do (to make sure that the ignition coil is truly fried.
The next step is to simply swap the ignition coil (that didn't spark) with another and then check for spark again. For this test and a better explanation of it, go to: TEST 2: Swapping Ignition Coils.