TEST 1: Testing For Spark

Testing For Spark. How To Test The Coil on Plug Ignition Coil (Honda 3.0L)

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):

  1. 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.
  2. 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.
  3. 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... so then, the very first thing that has to be done is to:

  1. Remove the first Coil-on-Plug ignition coil (which one? it doesn't matter since you're gonna' test them all).
  2. Attach the HEI spark tester (or an equivalent spark tester) to the Coil-on-Plug ignition coil (as shown in the photos in the image viewer).
  3. Attach the HEI spark tester to a good ground point by using a battery jump start cable (my preferred method).
  4. Have your helper crank the engine while you observe the spark tester.
  5. After noticing the result, which will be either spark or No spark, disconnect the spark tester and put the ignition coil back in place.
  6. Repeat the test for all of the remaining Coil-on-Plug ignition coils.
  7. You're gonna' get one of two results: spark or No spark.

Interpreting The Results

CASE 1: If you got spark, from all of the Honda Accord's (or Odyssey's) Coil-on-Plug ignition coils, then the ignition coils are good. The cause of the misfire is something else. Go to TEST 5.

CASE 2: If you got spark, from some but NOT all of the Honda Accord's (or Odyssey's) Coil-on-Plug ignition coils, then 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 and the Triggering Signal. Go to TEST 2.

CASE 3: If you got NO spark, from none of the Honda Accord's (or Odyssey's) Coil-on-Plug ignition coils, then the cause of your Honda's NO START Condition is not due to the ignition coils. It is rare (next to impossible) for all of the ignition coils to go BAD at the exact same time. Testing this condition is beyond the scope of this article but possible causes could be a BAD Crankshaft Position Sensor, BAD Ignition Switch, etc.

TEST 2: Testing The Power (12 V) Circuit

Making Sure The Ingition Coil Is Getting Power. How To Test The Coil on Plug Ignition Coil (Honda 3.0L)

OK, you're here because in TEST 1 you got a NO SPARK result from one of several ignition coils. The next step is to verify that that ignition coil or coils are receiving power.

Testing for Power can be accomplished by testing the COP coils connected or disconnected to their connectors. The method I recommend to use is with them connected to their connectors and with a Wire-Piercing Probe (to see what this tool looks like, click here: Wire-Piercing Probe. Now, if you decide to unplug the connector to test the front of the female terminal (of the connector) for 12 Volts, be careful not to damage it.

  1. Remove the Coil-on-Plug ignition coil that did not spark and connect the HEI spark tester to it (although you're no longer testing for spark, the spark tester must be connected just as a safety precaution).
  2. The three wires in the ignition coil's connector are usually sheathed in a hard plastic tube, remove enough of this plastic tube to expose the three wires for testing.
  3. With the ignition coil connected to its connector.
  4. Put the multimeter in VOLTS DC mode.
  5. Probe the circuit labeled with the number 1 (see photo in image viewer) with the red multimeter test lead (using an appropriate tool to pierce the wire).
  6. With the black multimeter test lead probe the battery negative (-) terminal.
  7. Have your helper turn the key to the ON position.
  8. You should see 11-12 Volts on your multimeter, or if you're using a test light, the test light should light up.

Let's take a look at what your test results mean:

CASE 1: If the multimeter registered 11-12 Volts (or the test light lit up), then the power circuit is OK and is delivering voltage. The next step is to test the ground circuit, go to TEST 3

CASE 2: If the multimeter DID NOT register 11-12 Volts (or the test light DID NOT light up), then the power circuit has a problem. This result eliminates the COP ignition coil as the source of the misfire condition. The power circuit is shared by all of the COP ignition coils.

TEST 3: Testing The Ground Circuit

Making Sure The Ingition Coil Is Getting Ground. How To Test The Coil on Plug Ignition Coil (Honda 3.0L)

OK, you're here because in TEST 2 your multimeter (or test light) confirms that the power circuit is OK. The next step is to verify that that ignition coil's ground circuit is doing its job.

Testing for ground can be accomplished by testing the COP coils connected or disconnected to their connectors. The method I recommend to use is with them connected to their connectors and with a Wire-Piercing Probe (to see what this tool looks like, click here: Wire-Piercing Probe. Now, if you decide to unplug the connector to test the front of the female terminal (of the connector) for ground, be careful not to damage it.

With the Coil-on-Plug ignition coil that did not spark already removed and still connected to the HEI spark tester and to its connector:

  1. Put the multimeter in VOLTS DC mode.
  2. Probe the circuit labeled with the number 2 (see photo in image viewer) with the black multimeter test lead (using an appropriate tool to pierce the wire).
  3. With the red multimeter test lead probe the battery positive (+) terminal.
  4. You should see 11-12 Volts on your multimeter, or if you're using a test light, the test light should light up.

CASE 1: If the multimeter registered 11-12 Volts (or the test light lit up), then the ground circuit is OK. The next step is to verify that the ignition coil is receiving the Triggering Signal, go to TEST 4.

CASE 2: If the multimeter DID NOT register 11-12 Volts (or the test light DID NOT light up), then the ground circuit has a problem. This result eliminates the COP ignition coil as the source of the misfire condition. The ground circuit is shared by all of the COP ignition coils.