4 Symptoms of a Bad Ignition Control Module
If your car has trouble starting or runs rough, it may not be that your battery or fuel system is the problem. Rather, your Ignition Control Module (ICM) is the culprit.
If this situation finds you in, keep reading. We’ll look at the most common signs of a failing ignition control unit, whether you can keep driving, and most importantly, how much it might cost to repair.
What is an Ignition Control Unit? Your engine’s ignition control module serves a very important purpose. This device is used to control the ignition timing and ignition of each individual cylinder in your internal combustion engine. Without this spark, combustion is not possible.
Simply put, the ignition control module is responsible for activating your engine’s ignition coils at the correct time and the correct discharge rate.
The ignition control module uses input signals from various sensors, such as the crankshaft position sensor and camshaft position sensor, to determine the proper engine speed before activating the ignition coils. Calculating this information is crucial, as it allows the distribution of spark to each cylinder at the exact moment when ideal combustion is possible.
In some applications, the ICM has been largely replaced by a more complex PCM. Many modern PCMs can now calculate the same information, and therefore control the coil actuation in the same way as the previous ignition control module.
Therefore, in the near future, the various ignition control modules will almost certainly be a thing of the past.
Symptoms of Ignition Control Module Failure When an engine’s ignition control module begins to fail, it can cause a variety of secondary problems, ranging from minor inconveniences to major issues. It is important to recognize these warning signs so that you can make a proper diagnosis before the problem becomes serious.
Here are some of the most common symptoms that indicate a defective ignition control module:
#1 – Check Engine Light Illuminated
In most cases, a fault in your engine’s ignition control module will cause your vehicle’s check engine light to illuminate. This is usually due to a record of random or cylinder-specific misfire errors.
#2 – Rough Idle/Poor Performance
If your engine’s ICM is not functioning, it is common for your vehicle to idle rough or erratically. Likewise, a faulty ignition control module will often cause a noticeable decrease in overall engine power and performance.
#3 – Engine Stalling
In severe cases, a defective ignition control module can also cause random stalls. This occurs when the module in question does not provide any kind of spark distribution associated with ignition, resulting in combustion being completely choked.
#4 – Starting Issues
As with the above issue, if the failure of the ICM in question is severe enough, the vehicle may experience starting issues. In such a situation, the affected module will fail completely, preventing spark from reaching each cylinder.
What causes a module to fail? Most cases of ignition module failure have a few things in common. One of the most common causes of ignition module failure is a poor ground connection.
Most ignition control modules are located inside the engine compartment of a vehicle, so heat and vibration are natural enemies of this type of module. It is important to note that excessive power supply from an overloaded generator can be another cause of ignition control module failure.
Can I still drive with a defective ICM? Assuming you can start and drive your vehicle despite having a defective ICM, then theoretically you can. This can result in a number of drivability issues of varying degrees of notice.
In the worst case scenario, attempting to drive a vehicle with an ignition control unit known to be defective could quickly find you stranded on the side of the road. If your engine’s ignition control unit fails while you’re driving, it will lose all spark related to ignition. As a result, combustion will stop.
That way, you may avoid the need to call a tow truck in the near future. If you’re not comfortable performing these repairs yourself, it’s best to schedule an appointment with a reputable auto repair shop as soon as possible.