Cummins Engine Shuts Down While Driving (7 Problems)

Cummins engines are some of the most capable and powerful diesel power plants on the planet. But, every Goliath comes across problems once in a while. Has your Cummins engine been shutting down while driving recently and leaving you frustrated? Then, you have come to the correct place.

In this article, we will explore the most common problems that can cause Cummins engines to shut down while driving. Not only that, you will learn some tips on how you can avoid it as well.

Overall, issues with fuel pressure, problems with the PCM, electrical gremlins, and running out of fuel are a few of the key issues that cause Cummins engines to have problems and shut down while you are driving down the road. Make sure to keep an eye out for these problems if you own a Cummins-powered automobile.

History of Cummins Engines

Diesel is not dead; it's part of the path forward | Cummins Inc.

Before diving head first into the causes of Cummins engine shutdowns, let us first give you an overview of this infamous engine manufacturer.

The origins of Cummins run all the way back to 1919 when an American mechanic by the name of Clessie Cummins caught the bug of building his own diesel powerplant. He built these engines under license from a Dutch manufacturer named Hvid.

Cummins started off by building agricultural engines but moved to the automotive sector in the early 1930s. Not content with building just road cars, the American manufacturer decided to take on motorsports too!

The 1931 Indy 500 saw the entry of a Cummins race car for the first time. The diesel-powered Duesenberg qualified for the race in P17 and ultimately crossed the finish line in 13th place. This started off the decades-long tradition of Cummins-powered vehicles participating in the Indianapolis 500.

Arguably, Cummins engines gained the most notoriety by being the powerplant of choice for RAM pickup trucks. This legendary partnership started in 1981 when Chrysler decided to put a Chrysler B-series six-cylinder under the hood of the newly refreshed Dodge RAM.

The partnership between Cummins and RAM continues to this day. The performance of these engines has only gone up year by year, with the current crop of powerplants producing well over 1000 lb-ft of torque.

Common Problems That Lead To Cummins Shutting Down While Driving

With that brief history lesson out of the way, let us get to the heart of today’s question. What causes Cummins engines to shut down while driving?

As you might have already guessed, there are many problems that can lead to this common issue. However, our research points to the ones mentioned below as the most widespread culprits that affect many Cummins engine owners around the world.

  • PCM Issues
  • Fuel Pressure Issues
  • Faulty Fuel Pump
  • Problems With The Alternator
  • Ignition Problems
  • Electrical Problems
  • Empty Fuel Tank

Now, we will take you through each of these issues. This will help you better understand how they cause the engine to shut down unexpectedly.

PCM Issues

The PCM (Powertrain Control Module), also known as the ECM (Electronic Control Module) is one of the most important parts of a Cummins engine. It is the main electrical controller engine.

As you can understand, failure of this component can lead to a whole host of issues, one of them being sudden engine shutdowns. There are several reasons that cause Powertrain Control Module failure. One of them is adverse environmental conditions.

The PCM of your Cummins engine is similar to a circuit board. As a result, it is susceptible to water and moisture damage. When either water or moisture comes into contact with the metal components of the PCM, it leads to corrosion. Not only that, but it also leads to short circuits as well.

Adverse environmental conditions can also result in your PCM getting permanent damage. Both extreme heat and sub-zero temperatures can result in PCM failures. In addition, excessive vibrations that you encounter on the road may also cause irreversible harm to the PCM, bringing your engine to a halt in the process.

Similar to other components of your Cummins truck, the PCM also has a finite lifespan. If the part has reached the end of its life, sudden engine stops while driving will be commonplace.

The easiest way to identify whether PCM issues are behind the engine shutdowns is by reading the engine error codes. Usually, error codes P0600 through P0606 indicate that there is a problem with this important electrical component.

Fuel Pressure Issues

Problems with the engine fuel pressure are another reason why you may experience Cummins shutting down while driving. This is mainly the result of fuel rail pressure sensor failure.

In addition to frequent engine shutdowns and stalls, some other symptoms of Cummins fuel pressure problems include bad fuel economy, startup issues, illuminated check engine lights, and black smoke coming from the exhaust tips.

If you notice any of these symptoms with your Cummins engine, it might be high time to have a look at the fuel pressure.

Faulty Fuel Pump

Similar to the fuel filter, the fuel pump can also play a major role in making your Cummins stop without warning. Fuel pump failures do not illuminate the check engine light, which makes diagnosing this issue even more difficult.

If you suspect that the issue lies with the fuel pump, all you have to do is to turn the key in the ignition. Ideally, you should hear the sound of the fuel pump prepping the fuel system. If that sound can’t be heard, you’ll have to spend some money on a replacement fuel pump.

Problems With The Alternator

The alternator is in charge of recharging the battery while the engine is running. However, if there is an issue with the alternator, it might impact the ignition system. As a result, the Cummins engine will shut down while you are driving down the road.

Ignition Problems

Speaking of the ignition system, it is one of the most important areas to keep an eye out for in order to prevent unexpected engine shutdowns. The ignition creates the spark which ignites the air-fuel mixture inside the cylinders. The resulting explosions propel the vehicle forward.

Problems with the ignition system can also cause your Cummins to unexpectedly shutdown in the middle of the road. On most occasions, issues within the ignition system’s components such as the crankshaft position are the ones to blame.

Electrical Problems

In addition to the electrical-system-related issues we already discussed, other electrical issues like loose battery terminals, blown fuses & relays, sensor issues, or even a dead battery can all end up causing your engine to turn off while driving.

Empty Fuel Tank

Although it might sound obvious, running out of fuel is one of the most common ways Cummins drivers get stranded on the side of the road. So, make sure that you have enough fuel in the tank before setting off on your journey.

With that out of the way, we will now give you some tips on how to limit unexpected Cummins engine shutdowns in the first place.

Preventive Tips To Avoid Cummins Shutting Down While Driving

Perform Regular Maintenance

The best way to save yourself from the trouble of your engine shutting down in the middle of the road is to perform maintenance work when it is due. Make sure to regularly go through the coolant and engine oil levels, as well as to clean out & drain the strainer and water-separating fuel filters.

When the engine reaches 125 hours of service, have a thorough look through the pump belt, air cleaner, as well as zinc anodes. Don’t hesitate to swap out any components that have gone bad. Additionally, it is a good idea to go through the different electrical connections at this point as well.

The next major service of a Cummins engine comes at 250 hours. Here, you should replace the engine oil, oil filters, engine-mounted fuel filter, as well as the water and fuel separator element. Not only that but make sure to inspect the antifreeze levels and the seawater pump too.

After the Cummins engine has completed 500 hours or 1 year of service, it is time for the next major maintenance work to take place. At this point, all the aforementioned elements have to be inspected first. Then, you can move on to other steps, like checking and replacing the drive belts and belt tensioners. In addition, the manufacturer recommends flushing out the heat exchanger, aftercooler, and gear oil cooler at this point.

By taking care of your Cummins powerplant in this manner, the risk of sudden shutoffs can be significantly reduced. If you currently own a Cummins-equipped vehicle or are planning of purchasing one in the near future, make sure to keep this useful information in the back of your mind.

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5 Common Cummins DEF System Problems (Preventive Tips)

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Mahir Ahmed


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