If you've been wondering how to test the Coil-On-Plug ignition coils on your Honda Accord or Honda Odyssey (2000, 2001, 2002, 2003 -3.0L V6) to see if one or several are bad and are causing a misfire, this is the article for you.
As is the custom here at easyautodiagnostics.com, the tests steps are explained in detail and the diagnostic/troubleshooting is accomplished in several easy steps.
This info applies to the 2000, 2001, 2002, and 2003 Honda Accord or Honda Odyssey with the 3.0L 6 cylinder engine. If you'd like to read a primer on how to test Coil-On-Plug ignition coils that are not covered by this article, take a look at this tutorial: Testing And Troubleshooting 3 Wire COP Ignition Coils.
Contents of this tutorial:
- Common Symptoms Of A Bad Coil-On-Plug Ignition Coil.
- What Tools Do I Need?
- Circuit Descriptions Of The C-O-P Ignition Coil Connector.
- TEST 1: Testing For Spark.
- TEST 2: Making Sure The Ignition Coil Is Getting 12 Volts.
- TEST 3: Making Sure The Ignition Coil Is Getting Ground.
- TEST 4: Testing For The Presence Of The Triggering Signal.
- TEST 5: Testing The Triggering Signal Without A Multimeter.
- TEST 6: Checking For Carbon Tracks.
You can find this tutorial in Spanish here: Cómo Probar Las Bobinas De Encendido (2000-2003 3.0L V6 Honda Accord y Odyssey) (at: autotecnico-online.com).
Common Symptoms Of A Bad Coil-On-Plug Ignition Coil
This is not the most definitive list on the subject, but does cover the majority of symptoms I've seen on this type of ignition system:
- Misfire codes that light up the check engine light (CEL) on your instrument cluster.
- Engine misfire that DOES NOT light up the check engine light (CEL).
- Smell of unburned gasoline coming out of the tailpipe.
- Rotten egg smell coming out of the tailpipe. This is due to the unburned gasoline from the misfiring cylinder over loading the catalytic converter.
- Really bad gas mileage.
- Lack of power as you accelerate the vehicle down the road.
What Tools Do I Need?
A scan tool (Automotive Diagnostic Scanner) is not needed. Even if you suspect a misfire, you don't need a scan tool to find out which cylinder is the one that is misfiring. You can perform the cylinder balance test yourself on your Honda Accord or Honda Odyssey, TEST 1 will help you with this. You'll need:
- An HEI spark tester.
- Battery jump start cables.
- A digital multimeter.
- This multimeter must be able to read Hertz frequency.
- A helper.
- You'll need someone to help you crank the engine while you perform the tests in the engine compartment.
- A repair manual.
- For whatever remove and replace info you'll need that is not covered by this article.
Circuit Descriptions Of The C-O-P Ignition Coil Connector
OK, to test the Coil-On-Plug ignition coils on your Honda Accord (Odyssey), you need to know what each wire (circuit) does in the connector. Here are the circuit descriptions:
- Circuit labeled 1:
- Power (12 V) Circuit.
- Circuit labeled 2:
- Ground Circuit.
- Circuit labeled 3:
- Trigger Signal Circuit.
The above circuit descriptions are shared by all of the six Coil-On-Plug ignition coils on your Honda Accord (or Odyssey). So, whether you're testing the number 1 cylinder ignition coil or the number 4 cylinder ignition coil (or whichever ignition coil), the above info applies.
To test these circuits, it's not necessary to unplug the ignition coil's connector therefore, I recommend testing for each signal with the connector connected. Also, using a wire-piercing probe is the most effective and easy way of getting to the signal. If you need to see what this tool looks like, click here: Wire-Piercing Probe.
TEST 1: Testing For Spark
This a pretty straight forward test, but one that has to be done with the HEI spark tester. Here are a couple suggestions that'll help you to avoid wasting money and time (by not replacing a good part):
- Do not use a regular spark plug instead of a dedicated spark tester. The result you may get from using a regular spark plug IS NOT trustworthy.
- Do not pull the ignition coil off of its spark plug, as the engine is running, to see/hear if it's sparking. This method can ruin/fry the ignition coil and now you've got another problem on your hands.
- I don't recommend using any other type of spark tester. Buy the HEI spark tester, not an imitation or something similar.
OK, now on with the show, I'm gonna' assume that you don't know which cylinder is the one that is misfiring or with the bad ignition coil or coils.
These are the test steps:
Remove the first Coil-On-Plug ignition coil that you're going to test.
Attach the HEI spark tester (or an equivalent spark tester) to the ignition coil as shown in the photo above.
Connect the spark tester to the battery negative (-) terminal. You can do this with a battery jump start cable (my preferred method).
Have your helper crank the engine while you observe the spark tester.
You're gonna' get one of two results: spark or no spark.
Disconnect the spark tester from the ignition coil and put the ignition coil back in place.
Repeat the spark test on the remaining ignition coils.
Let's examine your test results:
CASE 1: All six ignition coils sparked. This is the correct and expected test result.
With this test result you can conclude that all 6 ignition coils are good. The cause of the misfire is something else. Take a look at the suggestions here: TEST 6: Checking For Carbon Tracks.
CASE 2: You got spark from some but NOT all of ignition coils. The ones that did not fire off spark are probably bad.
To make sure, you need to verify that the ignition coil (the one that did not spark) is receiving 12 Volts, Ground and a Triggering signal. Go to: TEST 2: Making Sure The Ignition Coil Is Getting 12 Volts.
CASE 3: You got NO spark from none of the Honda Accord's (or Odyssey's) Coil-On-Plug ignition coils. It is rare (next to impossible) for all of the ignition coils to go bad at the exact same time.
The most likely causes of this are:
- A bad crankshaft position sensor.
- A bad ignition switch.
- A blown fuse.