How to Check an ESC with A Multimeter

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As you may know already, modern cars these days are geared with a wide array of electronic modules and sensors to control the different engine functions needed for the car to work. One of those parts is the electronic spark control module, commonly known as the ESC module or the ignition module. 

Keep in mind that the ignition model works with the computer to time the car engine’s ignition system for the best efficiency and performance. One of the particular functions of the ESC module is to retard or advance the ignition system’s timing, depending on the operation conditions.

The module will accelerate the timing under heavy load to boost power and will retard it at low throttle and cruising paces to make the most of its efficiency. The ESC module makes such adjustments efficiently and automatically, nearly to the point where they are undetectable to the driver.

You see, the ESC module plays an integral role in the engine’s operation. However, issues with it could cause problems with the vehicle’s performance and drivability. Normally, a failing or bad ESC module will create some symptoms, informing the driver of a possible problem that must be serviced. 

What is an ESC Module? 

As highlighted earlier, the electronic spark control (ESC) module is one of the many parts of a car’s ignition system. It works together with the ignition control module. Please take note that it varies depending on many factors, such as engine load. It also alerts the distributor to retard or advance timing. 

When combustion inside the engine doesn’t handle the wire, an abnormal vibration or “spark knock” occurs. If such vibrations caused by misfires aren’t minimized, they could cause serious damage to the engine’s components. 

Modern engines are now tuned to lower such knocks as much as possible. Nonetheless, they can still happen under specific scenarios. As an engine age, its timing could degrade as well, resulting in knocks. Further, outside factors like altitude and the humidity where the engine is operating could also cause timing problems. ESC compensates for such incidents. 

The vibrations which could damage an engine help make knocks simple to locate. They can be sensed and discovered when they happen as these vibrations resonate at a specific frequency. Knock sensors inside an engine have piezoelectric crystals tuned to that frequency and produce electric signals when the vibration happens. 

One sensor alone could locate engine knocks, but two or more are often utilized in an engine. Numerous sensors in various locations enable the ESC module to find the source of the knock with utmost accuracy.

How Can You Determine If Your Engine’s ESC is Not Working or Malfunctioning?

Here are some obvious signs your ESC is going bad. 

  • The car does not spark or start

A no spark or no start condition is a common sign that you are having a faulty ESC. Remember that the ESC module is a component, which controls engine spark. Hence, it could leave your car without a spark if it fails. 

A car without a spark might still crank, but it won’t run or start anymore. 

  • The engine is delaying

Engine delay is another symptom of a failing ESC. A faulty and malfunctioning ESC module might cause your engine to stall, leading to not starting again. The car’s engine could often be restarted after a short time, typically after the ESC module has been permitted to cool off. 

  • You experience more engine performance problems

This is one of the most typical and common signs of a malfunctioning ESC module. Do you notice the ignition module fails? Maybe you discover issues that could result in performance problems with the car like lowered fuel economy, loss of power, hesitation, or misfires. If yes, you need to check your ESC right away. 

How Do You Check an ESC with a Digital Multimeter?

When you have a damaged motor or ESC, most of the time, it can be difficult to determine whether the motor or ESC is damaged. Sometimes, it’s obvious. The way it works is that by swapping the motor, and if the motor still does not spin right, you assume it is the ESC. 

This section will present you with a simpler way to figure that out, all by using a multimeter. Follow the steps below, so you are guided properly.

  1. Take your digital multimeter and put it into continuity test mode. Touch the probes together, and you will get a beep sound. 

Remember that the way ESC works is the electricity comes in the main power lead, and it goes to MOSFETs—a small electrical switch that switches the flow of electricity on and off. Basically, the MOSFETs switching on and off drives the motors and drives electricity flow out the individual motor pads and makes the motor spin. 

Generally, you shouldn’t have electrical connectivity when such MOSFETs are powered down.  

  1. Now, test the connectivity between the positive and the motor outputs and the negative pad and the motor outputs. You can do this with the ESC module still mounted in the quad. You can use your XT60 plug. 
  1. Test the positive and each of the motor pads for connectivity. Do the same thing for the negative side and teach each of the motor outputs. If you test your ESC and have continuity between the negative or the positive and any other outputs, you certainly have a bad or damaged FET. 

But remember that even if you have continuity does not indicate the ESC is good. If you do have continuity, it indicates the ESC is fried. 

Final Thoughts

To sum up, the electronic spark control module is one of the most critical parts seen in any modern ignition system. Without this component, many vehicles will not operate smoothly. Do you believe your ESC module might be having some problems too? It will help if you have your car checked by a professional technician to find if it needs an ESC replacement. 

We hope you find this post helpful and informative. Please share your thoughts with us by leaving your comments down below!

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