How To Test The Ignition Control Module (1998-1999 3.0L V6 Honda Accord)

How To Test The Ignition Control Module (1998, 1999 3.0L V6 Honda Accord)

The ignition control module (ICM) works hand-in-hand with the ignition coil to create spark, and when it fails, the engine won't start.

So, if your 3.0L V6 Honda Accord cranks but won't start —and you've ruled out basic stuff like fuel delivery— there's a good chance the ignition control module is the problem.

In this tutorial, I'll walk you through step-by-step tests to confirm whether the ignition control module is working or not.

You'll only need a multimeter and a 12V test light (or an LED test light for the last step).

Let's start from the beginning and find out what's really going on under that distributor cap.

APPLIES TO: This tutorial applies to the following vehicles:

  • 3.0L V6 Honda Accord: 1998, 1999.
  • 3.0L V6 Acura CL: 1997, 1998, 1999.

IGNITION SYSTEM WIRING DIAGRAM: The following wiring diagram complements the info in this tutorial.

Symptoms Of A Bad Ignition Control Module

The most common symptom of a bad ignition control module on the 1998–1999 3.0L V6 Honda Accord is a no-start condition —where the engine cranks strongly but doesn't start. That's because when the ignition control module fails, it stops triggering the ignition coil, and without spark, the engine can't fire.

Sometimes, though, the failure isn't complete. A failing ignition control module can act up intermittently —causing the engine to start and run fine one moment, then suddenly refuse to start the next. This kind of random no-start can drive you nuts, especially if spark returns by the time you start testing it.

Here's a quick list of symptoms that point to a bad or failing ignition control module:

  • Engine cranks but won't start.
  • No spark at any of the spark plug wires.
  • Intermittent starting problems that come and go without warning.
  • Backfiring or rough running right before total failure (in some cases).

If you're seeing any of these symptoms, the step-by-step tests in this tutorial will help you pinpoint whether the ignition control module is truly the issue —or if something else is at play.

If you're troubleshooting an engine no-start problem, I've got a full tutorial that dives deeper into the most common causes, how to test them and resolve them:

TEST 1: Making Sure The Ignition Control Module Is Getting Power

Making Sure The Ignition Control Module Is Getting Power. How To Test The Ignition Control Module (1998, 1999 3.0L V6 Honda Accord)

The first thing we're gonna do, to get our ignition control module diagnostic started, is to confirm that it's getting power (10 to 12 Volts DC).

The wire that delivers it, is the black with yellow stripe (BLK/YEL) wire when the key is in the ON or RUN position.

It's important to know, that this voltage first arrives at the ignition coil, and then inside the ignition coil, it's internally routed to the ignition control module.

So if there's no power here, both the ignition control module and ignition coil won't work —period.

IMPORTANT: If the spark plug wires are firing spark, then the ignition control module is functioning. If you haven't checked for spark yet, do so first. This tut will help you with that: How To Test The Ignition Coil And Basic System Checks (1998-1999 3.0L V6 Honda Accord).

Here's what we need to do:

  1. 1

    Turn the key to the ON position, but don't crank the engine.

  2. 2

    Disconnect the 3-wire electrical connector that plugs into the distributor.

    IMPORTANT: Make sure the ignition coil stays connected to its own 3-wire connector.

  3. 3

    Set your multimeter to DC Volts mode.

  4. 3

    Connect the black lead to battery negative (-) post.

  5. 4

    Gently probe the front of the female terminal that connects to the BLK/YEL wire with the red multimeter test lead.

  6. 5

    You should see 10 to 12 Volts with the key in the ON position.

Let's break down what your results mean:

CASE 1: You got 10 to 12 Volts on the BLK/YEL wire. That confirms the ignition control module is receiving power, so you're good to move on to the next test.

The next step is to check if the ignition coil is getting the activation signal. Go to: TEST 2: Checking The Ignition Coil's Activation Signal.

CASE 2: You did NOT get 10 to 12 Volts on the BLK/YEL wire. That means the ignition control module has no power and won't work without it.

Check Fuse #6 (30 Amp) in the under-dash fuse and relay box. If the fuse is blown or there's an open in the BLK/YEL wire circuit, that's the root of your no-start issue. Your next step is to fix the power supply.

TEST 2: Checking The Ignition Coil's Activation Signal

Checking The Ignition Coil's Activation Signal. How To Test The Ignition Control Module (1998, 1999 3.0L V6 Honda Accord)

Now that you've confirmed the ignition control module is getting power, the next step is to make sure it's doing its job —activating the ignition coil.

Here's how it works: when the PCM tells the ignition control module to fire, the ignition control module sends an ON/OFF pulsing signal to the ignition coil through the BLU wire.

To be a bit more specific, that pulse isn't voltage being sent to the coil —it's the ignition control module rapidly switching the ignition coil's Ground circuit ON and OFF, based on the PCM's timing commands. This is what causes the coil to fire spark at just the right moment.

If that ON/OFF pulse is missing, the coil won't fire —and you'll have an engine no-start condition on your hands.

In this test, you'll use a 12 Volt test light to check for that pulsing activation signal while cranking the engine. If you don't have one, here's the one I recommend:

NOTE: Both the ignition control module and ignition coil must remain connected to their connectors to read the ignition coil activation signal.

Let's see if the coil is being told to fire.

  1. 1

    Reconnect the ignition control module to its 3-wire connector.

    NOTE: Make sure the ignition coil is connected to its 3-wire connector too.

  2. 2

    Clip your test light to the battery positive (+) terminal.

  3. 3

    Connect the tip of the test light to the BLU wire of the ignition control module's connector.

    NOTE: You'll need to pierce the BLU wire's insulation with the test light probe. Make sure to pierce it several inches away from the connector itself (this is important).

  4. 4

    Have your helper crank the engine while you watch the test light.

  5. 5

    The 12V test light should flash ON and OFF as long as the engine is cranking.

  6. 6

    When done, wrap a small piece of black electrical tape around the spot where you pierced the BLU wire.

Here's what your results mean:

CASE 1: The test light flashed ON and OFF while cranking. That means the ignition control module is working —it's sending the correct activation signal to the ignition coil.

At this point, you can confidently say the ignition control module is good (since it's getting power and it's activating the ignition coil). If you're still not getting spark, the ignition coil itself is bad.

If the ignition coil is sparking away, then the engine's no-start problem is caused by something else. Your next move is to start checking the other systems that affect starting —like fuel delivery and engine mechanical condition:

CASE 2: The test light DID NOT flash at all. This means the ignition control module is not sending the activation signal to the ignition coil.

The next step is to find out whether the ignition control module is receiving its own activation signal from the PCM. Go to: TEST 3: Making Sure The Ignition Control Module Is Getting An Activation Signal From The PCM.

TEST 3: Checking The Ignition Control Module's Activation Signal

Checking The Ignition Control Module's Activation Signal. How To Test The Ignition Control Module (1998, 1999 3.0L V6 Honda Accord)

The PCM plays a central role in spark control. Once it detects crankshaft position (CKP) and both camshaft position (CMP) signals, it knows the engine is cranking and calculates when each cylinder should fire.

It then sends an activation signal to the ignition control module, which in turn activates the ignition coil.

In this test, you'll use an automotive LED test light to check if the PCM is sending that signal to the ignition control module.

Don't have an LED test light? Here's one I recommend:

NOTE: Both the ignition control module and ignition coil must remain connected to their connectors to read the ignition control module's activation signal.

Here's how to check it:

  1. 1

    Connect your LED light's red wire to the battery's positive (+) post.

    NOTE: If the red wire isn't long enough, use a jumper wire to extend it so it can reach the battery terminal.

  2. 2

    Connect the black lead of the LED to the yellow with green stripe (YEL/GRN) wire.

    NOTE: You'll need to use a probe to pierce the YEL/GRN wire and then connect the black wire of the LED to the probe.

  3. 3

    Have a helper crank the engine while you watch the LED light.

  4. 4

    The LED light should flash ON and OFF the entire time your helper is cranking the engine.

Here's what your results mean:

CASE 1: The LED flashed ON and OFF while cranking. That tells you the PCM is doing its job —it's sending the ignition control module a valid activation signal.

Since TEST 2 confirmed that the ignition control module is not activating the ignition coil —and TEST 1 confirmed it's getting power— this tells us the ignition control module has failed and needs to be replaced.

This is the replacement I recommend. It's from a well-known brand I've personally used in the field:

Buying through this link helps support this site at no extra cost to you

CASE 2: The LED DID NOT flash while cranking. That means the PCM isn't sending the ignition control module an activation signal.

This missing ignition control module triggering signal is usually caused by a failure in one of the key sensor inputs: either one of the camshaft position (CMP) sensors or crankshaft position (CKP) sensor isn't working.

Your next step is to test the CMP and CKP sensors. Here are the tutorials to these very easy tests:

TECH TIP: Use The Right Tool To Avoid Damaging The Connector

When testing the front of the terminals at the 3-wire connector on the distributor, it's a good idea to check whether the metal probe of your multimeter's test leads is too large for the terminal cavity.

Most multimeter test leads are a bit too thick to safely insert into the terminal opening without risking damage to the female terminal inside.

What you want to use instead is a thin, needle-like probe that can gently slip into the cavity and touch the metal terminal without forcing anything. This isn't just about tool preference —it's about avoiding a head-ache (intermittent false connection) down the road.

Is it really that important to test the front of the terminal? Should I just back probe the connector or use a wire-piercing probe on the wire? These are valid ways to check the signal in the circuit. I'll explain why I prefer and recommend testing the front of the terminal...

...I've had cases where the wire had broken off inside the connector —the copper strands snapped right at the crimp, but the insulation was still holding it in place. From the outside, it looked fine. But no signal was actually reaching the terminal because the wire itself was no longer attached. Testing at the front of the terminal is how you catch issues like this.

I'm not trying to sell you anything here —just sharing what I've encountered in the trenches day in and day out. If you're interested, here's the exact probe set I use myself to test without worries of damaging the connector:

In this kit, the wire piercing probe is made up of two parts and they can be disassembled. I use the part that's the needle probe (that pierced the wire's insulation) as the probe for my multimeter to check the metal terminals of connector cavities where standard multimeter test probes are too thick to use.

More 3.0L V6 Honda Accord Diagnostic Tutorials

Whether you're chasing down a check engine light or just want to understand your Accord a little better, this index is a great place to start. It's full of real-world how-to guides written with both DIYers and experienced techs in mind.

Here's a quick peek at some of the step-by-step tutorials you'll find there:

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