Ignition Control Module Testing With A MultimeterMintt
The Ignition Control Module is an electric switch that turns your ignition system “on and ” Off”. The ICM relies on a signal from a sensor that is located inside of the distributor which directs it to fire up the ignition coil. The ignition coil once fired up creates just enough energy for the spark plugs to do their job. The energy produced by the ignition coil should be strong enough to bridge the spark plugs together which in turn create enough voltage to ignite the idle air/fuel mixture in order to create a well timed combustion. In order to fire up the correct cylinder the ignition control module must control the timing of the spark so that it matches perfectly other wise it might cause an engine misfire.
How to identify the Ignition control module
Before proceeding please make sure that your vehicle is actually equipped with an ICM. Some cars depending on the model might not have an individual ICM but instead is controlled by the ECM also known as the Engine Control Module or the powertrain control module or the electrical control unit. The ICM is usually located inside of the distributor housing or on the right side of the engine compartment. If your car is not turning over or not running at all the best place to start might be with the bad ignition control module unit. Testing a bad ignition control module unit does not require an expreicend mechanic skills to test, so anyone that can do it in less than 5 easy steps.
Testing an ICM the easy way. Tools you will need.
- Wire Piercing probes
- Wiring diagram
- A Helping hand
- 12 volt test light
- New Ignition switch
How the check the ICM using your DVOM
Using the negative lead of the DVOM connects it to the auto metal frame. It must be grounded using a T pin or an alligator clips. Now have your second hand help crank the car while you are testing the different terminals for current.if there is no current passing on to the terminals then you might need a new ignition control module for you car.
Step 2 : Testing the spark plugs using a multi meter.
To check the spark plugs for current you will need to have the 12V test light ready and you will need to tap into the spark plugs terminals of your ignition control module. If your test light flickers that you will the need to keep on cranking up the engine so it can ramp up some voltage to keep it powered up. If after you plugin in the test light and it is not powered up or flickers then you might be in need of a new ignition control unit. Make sure that the battery voltage is optimal prior to testing
Step 3 : single out the control module issues
So now that you have noticed that you get no current with you ignition control module now what do you do? well here comes the hardest part of this whole process. First you need to start with what we call a “smell ” test. That’s right you will need to smell the unit ensuring that you do not have a module that is already burnt or a clogged distributor cap .
Using the Digital Volt Ohm Meter move the dial to the OHMS setting to test out the resistance of the two points. Locate the ignition module, with your wire piercing probe or alligator clips, tap into the wires going from/to the ignition system and spark plugs. If at any point during the test you get an infinite reading on your DVOM then you can conclude that the ignition module ICM plug wires are faulty or you really need a new control unit, if not your ignition control module might not be the real problem with your vehicle check the distributor cap.
Once you are done with the wires, and you decided that you actually need some electrical wiring done you can easily do it yourself or get in touch with your local mechanic or take it up a notch and do a couple coil tests. Now if it is not a wiring issue you and you need to buy an ignition control module,Flagship one will be able to help you find it, as they have a large selection of control modules.