How To Test Your Ignition Control Module with a Multimeter.

What exactly is an (ICM) Ignition Control Module?

How To Test Your Ignition Control Module with a Multimeter

An ICM is nothing more than a switch that turns the ignition system “On” or “Off”. Inside of the distributor there is a sensor that sends out a signal to the ICM, which is then used to fire up the ignition coil that will create enough energy for the spark plugs. The spark must be strong enough to connect the gap between the spark plugs,therefore producing enough voltage to ignite the fuel/air mixture for a well timed combustion. The ignition control module must control the timing of the spark so that it is able to occur exactly at the right cylinder and the perfect moment. If you would like to know more about the ignition process you can do so by reading our next post.

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How to identify the Ignition Control Module.

The ICM location varies from make, to models and of course to the year the vehicle was built. Please note that some cars might not have a separate ICM but is instead controlled by the Engine Control Module (ECM) which goes by different names such as the Powertrain Control Module( PCM) / Engine Control Unit (ECU). Before going ahead and look for it. fire up your search engine and find out whether you have an Integrated Electronic Ignition system so you won’t end up reading this since it won’t be of any use.

Typically the Ignition Control Module is located inside of the distributor housing or mounted on the side of the engine compartment. Not to state the obvious, but once an engine module goes bad your vehicle will not run at all, but luckily you can fix that with the simplest of tools and in 3 easy to follow test.

Testing an Ignition module is easy so, here is what you will need

  1. Multimeter
  2. A wiring diagram of your vehicle(which can be found online)
  3. Wire Piercing probes
  4. A helper(to crank the engine)
  5. A 12 volt test light
  6. A replacement ignition switch**

As you can notice this list is simple and perfect if you’re trying to work with a budget.

Ignition Control Module  Multimeter

Step 1 : Check your ICM for current.

Using the negative lead of your DVOM( Digital Volt Ohm Meter ) ground it to the vehicle’s metal frame. PS : It MUST be grounded off a metal part of the car. Now have your helper crank the engine while you’re testing the different terminals for current. If there is no current being passed to the terminals sadly you will have to replace the entire ignition control module.

Step 2 : Check your ICM Spark Plugs ( ignition module ) for current.

To check the spark plugs for current, you will grab your 12v test light and tap into your spark plugs terminals. If your test flickers constantly when you crank the engine then you can go ahead and note that your plugs are in good working conditions. Now the problem is you will need to run a much more thorough test for the other components in your vehicle. No current? keep reading.

Step 3 : Isolate the problem.

You have had no current, now what? We’re going to have to check for continuity. I usually start by inspecting each wires for signs of break,burnt marks or any sorts of fraying these are usually the tell-tale signs.

Using your DVOM test switch to the OHMS setting and carefully retest the ICM wires again. Make sure you are testing the wires going from/to the ignition control module and spark plugs. If you are still getting an infinite reading off your DVOM then you can go ahead and conclude that your wires are faulty.

Once you’re done if it’s the wires that needs to be replaced it won’t be too much of a hassle to repair but you might end up needing the help of a qualified mechanic or you can easily do it yourself if you’re up for the challenge. Now if it is not a wiring issue or not an ignition coil issue and you’re in need of an ignition control module, you’re in luck because here at Flagship One we carry the nation’s largest inventory of ignition control module and better yet we have the most reasonable prices so be sure to check out our store or just give us a call at 516-766-2223 . Our experts are here to help!


Can you test an ignition control module?

Yes, You can definitely test an ignition control module and using a multimeter is one of the fastest way to do so.

What does the ignition control module do?

The Ignition Control Module or ICM is nothing more than a switch per se that turns the ignition system “On” or “Off”.

How do you test an ignition control module in GM?

Step 1 : Check your ICM for current.
Step 2 : Check your Spark Plugs ( ignition module ) for current.
Step 3 : Isolate the problem.

How do I know if my ignition control module is bad?

if you are not getting any current to or from your ICM your ignition control module is bad. Read our post and use a multi meter

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