It can be alarming if your engine shuts down while your driving. This can happen for a variety of reasons.
The key thing is that you don’t ignore the issues. If your car turns off while your driving you need to address the issue head-on.
In this post, I will go over 13 different reasons why your car might have shut down while your driving.
Let’s get started.
1. You Ran Out Of Gas
One of the most common reasons that a car dies while driving is because you ran out of fuel.
According to AAA, more than 500,00 people run out of gas every year.
Most of the time, our busy schedules make us forget to fill up the gas tank. Or it pushes us to run the tank on empty because we don’t have time to fill up.
So the first thing to do if your car shifts off while you are driving is to make sure your gas gauge is above the “E.”
If your gas is below the “E, “you have a straightforward explanation of why your car shut off.
A less common reason is that your gas gauge is faulty and cannot tell you you’re out of gas.
One of the common reasons you have a faulty gas gauge is due to a sending unit failure.
This will typically cause your fuel gauge to get stuck in one position regardless of the fuel level. This is typically at the “F” or “E”.
This is a challenging issue to identify if the gauge gets stuck on the “F.” But much easier to determine if the gauge gets stuck on “E.”
You’ll notice the next time you put gas in your vehicle because the gauge will stay on “E”.
2. Damaged Alternator
The alternator is the powerhouse of your car. If your alternator is not working correctly, then your vehicle will eventually stall and turn off.
Most people don’t realize that your battery does not run your car. Your battery is only designed to start your car.
The alternator recharges your battery and provides the electricity your car uses while your driving.
It’s important to note that your car can run without an alternator, so you might not realize right away that you have a problem.
If your battery is functioning properly after your alternator dies, your battery will step in to supply power.
Vehicles can only do this for a short period. Your battery is not designed to provide power to the entire car. Your car can only last a short period while running on the battery.
Once your battery dies, your car will stall and eventually shut off.
3. Broken Crankshaft Position Sensor
If you have a faulty crankshaft position sensor, then your car will stall and turn off on you.
You’ve probably never heard of the crankshaft position sensor. That’s because it work’s in the background.
This sensor helps with engine management. It tracks the crankshaft’s velocity and location to help facilitate the timing of fuel injection and ignition system.
If you have a faulty sensor, these systems in the engine will not work in sync. This will cause your engine to stall and turn off.
One way to determine if your crankshaft position sensor is broken, you can inspect your tachometer. If your tachometer is not working or giving a faulty measure, this is a sign that your crankshaft position sensor is faulty.
The tachometer is the gauge on your dashboard that reads the RPM’s in your vehicle. Its typically located next to your speedometer.
The tachometer typically increases every time you rev your engine. When you reach your ideal speed, the tachometer will stay in one place. If this is not working as it should, your crankshaft position sensor is faulty.
You can also check if your crankshaft position sensor is faulty by using an OBD scanner and reading the error codes from the ECU.
If you receive diagnostic trouble codes (DTC) between P0335 and P0338, then there is an issue with your crankshaft position sensor.
Using an OBD scanner is an easy way for both experts and beginners to determine their car’s issues.
This device will not always give you the exact issue, but it’s an excellent way to determine where the problem is starting.
4. Faulty Engine Control Unit (ECU)
The Engine Control Unit or ECU controls a series of mechanisms inside the engine for optimal engine performance.
The ECU is crucial to your car’s operations; without a functioning ECU, your car won’t run properly.
If you have a faulty ECU, you may drive for a short period, but your car is undrivable once it fails.
One of the common symptoms of a faulty ECU is your car stalling and jerking while driving. It’s also possible that your car will shut off randomly and turn back on.
This is because the ECU can cause sudden drops in power, fuel efficiency, and spark loss. These can cause your car to turn off and turn back on when the ECU is malfunctioning.
Unfortunately, testing and inspecting your ECU is not easy. The easiest way to determine you have a faulty ECU is with an OBD scanner. But DTC codes are not clear cut for a failing ECU. This makes diagnosing a faulty ECU difficult.
The best way to determine if you have a faulty ECU is to take your car to a mechanic. A mechanic will have the right tools, software, and understanding to diagnose your ECU.
5. Damaged Fuel system
A faulty or broken fuel system is another common reason cars shut off while driving. The primary function of the fuel system is to store and supply fuel to the engine.
If that fuel system does not supply fuel to the engine for any reason, then your car will turn off. This is very similar to running out of fuel. It’s simple without gas, your car won’t run.
The main concern with the fuel system is that any issues make your car undrivable.
For example, if your fuel pump stops working, the fuel in your tank will never reach your engine, and your car won’t start.
Other parts, such as the fuel filter and fuel supply line, create similar concerns.
If they are faulty or damaged, your car won’t receive the gas it needs. In most cases, your vehicle won’t be drivable or will continue turning off.
The best way to diagnose fuel system issues is to take it to a professional. Not only can they identify the issue, but they can also begin repairing your car.
6. Dead Battery
Another common reason that your car might shut off while you’re driving is due to a dead battery.
Your battery does not power your vehicle. It’s only used to start your car.
If your alternator is not working correctly, your car will use your car battery for electricity.
If your car battery is dead or not holding a proper charge, your car will die shortly after you car starts using your battery for power.
If your alternator is dead, your battery will not last very long.
The easiest way to check your car battery is using a multimeter. Your car should have a voltage of around 12.6 volts.
If your battery is showing anything less than 12.6v, then your battery is not fully charged.
If your battery is below 11.7v, you need a new battery. At 11.7v, your battery is holding less than 25% of its charge.
7. Faulty Spark Plugs
The spark plugs are key to starting your car. Your spark plugs provide the spark needed to convert chemical energy into heat to get your car started.
Without proper functioning, spark plugs your car won’ function properly.
Your car has as many spark plugs as cylinders. Each spark plug ignites the fuel in the cylinder to get it pumping.
With one faulty spark plug, it’s possible to start your car still and drive. But the issues arrises when you drive with faulty spark plugs.
This can cause issues with the crankshaft and cause your engine performance to decrease considerably.
If multiple spark plugs are faulty, your car may start, but it most likely won’t drive long. The imbalance can cause your engine to stall and turn-off.
Typically there will be several vital signs before your car reaches this stage: misfires, reduced engine performance, lack of acceleration, engine knock, among others.
You can read our in-depth article here for more detailed information on the key signs of bad spark plugs.
An easy way to determine if you have a bad spark plug is to inspect them. This can be easier or harder to do, depending on your car.
Once you can physically see your spark plugs, the condition of your spark plugs will be evident. Below is a guide you can use to track the condition of your spark plugs.
Resource: 6 Symptoms of Bad Spark Plugs
What To Do If Your Car Shutts Off While Driving?
Pullover your car to the side of the road
If your car shuts off while you are driving, don’t panic. Panicking can cause more stress than it should.
The first thing you should try and do when your car shuts off is trying to get off the road. Make your best effort to remove yourself from any traffic in the safest way possible.
If possible, find an empty parking lot to inspect your vehicle safely.
If you are pulled over on the side of the road. In almost every street or highway, the lane to the right is the safest place to pull over.
As soon as you experience your vehicle turn-off, turn on our emergency lights to notify other drivers that you are in distress.
In most cases, even if your car turns off, you will still have control over your steering wheel and brakes.
However, they may have less control and power than when the car is on.
Both the breaks and steering wheel rely on the engine for improved control. If your car does shut off, be cautious of this change and carefully steer and apply your breaks.
The emergency brake is manual and works regardless if the engine is off or on. You can use your emergency brake to help you stop if your brakes are not strong enough.
Try To Restart Your Car
If your car turns-off while you are driving, make sure that you try to restart it. In most cases, your car will turn back on.
Many people forget to try and turn on their car because they are worried about what just happened.
If your car does turn back on, it’s not recommended that you continue driving as you usually would.
Use this time to get off the road and park your car somewhere safe. This will give you time to inspect and determine why your car turned off.
Don’t ignore your issue; if your car turns off while driving is a sign of a larger problem. If your car turned off once while driving, the issue will likely resurface.
Use Emergency Lights, Flares, Or Cones
When your car turn-off, it’s crucial that you do everything you can to notify other drivers you are in distress.
As you are driving, make sure you turn on your emergency lights to alert other drivers. If your car is turned off because of a dead battery, then your hazard lights will not.
If this is the case, remember to be cautious as you try and get off the road.
Once you reach the side of the road, there are a few things you can do to keep yourself safe. This is particularly important if you are stranded on a busy street or highway, especially if it’s at night.
The best thing to do is to keep emergency cones or flares in your car.
Place these several feet behind your car and on the side of your car.
This will alert other drivers of where you are and give them a chance to react or slow down. Keeping emergency equipment such as flares or cones are valuable, and you should always keep one inside the trunk of your car.
Seek Asistance from Roadside or Emergency Services
If you’re stuck on the side of a road and there is no help in sight, it’s best to seek help.
The best places to seek help is from emergency services such as roadside assistance.
Most services, such as AAA, have 24-hour roadside assistance, which means you can get help at any time.
If you can get a hold of roadside assistance, you can also contact emergency services.
The cops will make sure that your car is safe. Cops can also help you contact roadside assistance if you don’t have service or your phone is dead.
Trips and getaways can be fun and exciting, but don’t let car problems ruin your plans. It may occur while you’re already on the road.
If and when your car dies on you, always keep in mind to be calm and relax. However, I know that it won’t be an immediate reaction.
Just pull yourself together, and focus on the next best thing to do: Turn on your hazards, move to a safe curb, and set up warning devices.
Once settled, try restarting your car again and think of your best options at the same time. If there’s none, call for help.