Car Turns Off While Driving but Turns Back On

Being unable to restart your vehicle after it shuts off while driving is a very risky situation to be in. With numerous complicated systems working together to keep your vehicle operating, it might be challenging to determine which part is causing your automobile to shut down while driving. However, there are a few frequent causes, some of which are straightforward to resolve. Possessing fundamental knowledge about your vehicle can assist you in addressing technical issues, especially when your car shuts off while driving.

In this article, we will be going over some helpful insight and tips to help you when your car turns off while driving but turns back on so you can prevent it from happening again in the future.

Why does my car turn off while driving but turns back on?

  1. Problems with your engine control unit

The Engine Control Unit, or ECU, is a crucial component of your car. This modest computer task controls the majority of the processes. ECU ensures that the vehicle operates efficiently and identifies any potential faults. The ability to regulate various engine processes contributes to optimal engine performance. However, if the vehicle’s computer malfunctions, the engine may lose power. If the ECU malfunctions, you will be unable to drive your vehicle. Occasionally, the car may randomly cut off and then restart.

This may occur if the ECU loses spark, power, or fuel economy. There are a variety of causes for computer malfunction. If there are any faults, the engine light will indicate. To establish whether the ECU is operating correctly, you must acquire an OBD scanner. Remember that diagnosing or checking your ECU might be extremely challenging.

  1. Faulty fuel pump

A fuel pump delivers the correct amount of fuel to the engine. If the gasoline pump fails to provide adequate power to the engine, the motor will shut down, leaving you stranded. The bad news is that a defective fuel pump cannot be bypassed; it must be repaired or replaced. Another possibility is that your fuel filter is clogged, preventing the fuel pump from pumping fuel. Oftentimes, a faulty fuel pump is the cause of a car that shuts off while driving and restarts out of nowhere.

A fuel filter is a minor component whose sole purpose is to purify the fuel that enters the engine. If the fuel filter is clogged, insufficient energy will enter the system, and the engine will shut down. Thankfully, it is simple to repair a fuel filter. The majority of fuel pumps are mounted within the fuel tank. A small mechanic’s trick is to give the fuel tank a kick with your foot or anything similar when the car shuts off. If the vehicle starts, there is likely an issue with the gasoline pump. The last thing you want to do is puncture the plastic gasoline tanks. 

  1. Driving on an empty fuel tank

A lack of fuel is one of the most common reasons for a car to shut down while travelling. In some circumstances, this will result from a fuel leak, while in others, the driver will be responsible for not filling the gas tank. It is also possible that the fuel gauge is malfunctioning and displaying erroneous information. Regardless of the reason, a car without fuel will not operate and will shut down regardless of location.

In the majority of automobiles, the fuel light illuminates when approximately 10 percent of the gasoline capacity remains. This is the initial notification that you should refill your gas tank. When there is no fuel remaining, there will be no visible indicators, save that the automobile will sputter for a few seconds before you realise that the gas pedal is no longer responsive. It would help if you acted swiftly to get the car to a safe stopping position before the vehicle begins decelerating. Once you have reached a safe spot, you must refuel the vehicle. Ensure you have sufficient fuel to reach the nearest gas station and fill the tank.

  1. Malfunctioning crankshaft position sensor

A malfunctioning crankshaft position sensor is an unexpectedly common cause for a vehicle to shut off while driving. The crankshaft position sensor monitors the engine’s numerous movable components, such as the crankshaft, engine valves, and pistons. It monitors the crankshaft’s velocity and position to facilitate efficient fuel injection and ignition timing.

This mechanism is vital for the optimal performance of your engine. A cylinder misfires as a result of a malfunctioning crankshaft position sensor’s inability to give the Engine Control Unit accurate information regarding piston position within the engine. If the crankshaft position sensor malfunctions, the check engine light may illuminate. Another indication that the crankshaft position sensor is defective is a malfunctioning tachometer.

The tachometer is the gauge situated next to the speedometer on the dashboard that displays the car’s RPMs. Every time you crank the engine, the tachometer will climb. When the desired speed is reached, the tachometer will remain still. After obtaining engine speed information from the crankshaft position sensor, the ECU will transmit data to the tachometer.

If the crankshaft position sensor malfunctions, it will give inaccurate data to the ECU, which subsequently causes the tachometer to begin functioning irregularly or intermittently. Other common signs of a defective crankshaft position sensor include decreased fuel economy and an engine running rough and misfiring before stalling out while driving.

  1. Complications with your vehicle’s battery

In addition to fuel, your car’s battery assists in starting the vehicle. The combustion process can be initiated by applying the proper amount of electricity. Even though the battery does not power the vehicle, it is nonetheless accountable for its creation. A car battery can power additional components. Your vehicle will shut down if the battery cannot be adequately charged. It would help if you determined whether or not the battery is dead.

In addition to halting your vehicle, short circuits can occur while driving. When the alternator is not operating, the battery will be utilised. With a dead battery, your vehicle will also die. If the alternator is not functioning, the battery will not last long. A multimeter will help you to determine the condition of the automobile battery. When the battery voltage falls below 12.6, it has not been fully charged. It must be replaced if the battery voltage drops below 11.7V and has less than 25 percent charge.

  1. Unexpected issues with your alternator

In addition to recharging the battery, the alternator supplies the majority of the electrical power your car requires when it is in motion. Before the engine dies, the first indicator of a failed alternator is when the ECU identifies a problem with the quantity of power coming from the alternator. This will cause the dashboard battery indicator to illuminate. Typically, the alternator delivers between 13 and 14.8 volts to the battery. The vehicle will not start, the headlights will dim, a charging system warning light will illuminate the dashboard, and the engine will die if the alternator is defective.

Approximately 3% of the battery’s charge is lost when the car’s motor is started. This leaves ample power to restart an engine or provide additional power if necessary. However, the battery must be charged while the vehicle is running. Otherwise, the battery will lose most of its remaining charge, resulting in irregular engine behaviour and possible shutdown.

  1. Broken timing belt

A damaged timing belt is a frequent cause of a vehicle’s loss of power while driving. Your car may exhibit poor timing belt symptoms prior to failure. If the timing belt fails, the engine will likely not start, and if it does, it will run poorly. Occasionally, a timing belt might become excessively worn and stretch significantly. This will alter the engine’s timing and may cause the timing belt to slip. A stretched timing belt will produce a low power output, especially under solid loads.

In addition, it can result in poor fuel economy and frequent engine misfires, which might cause the engine to die while driving. If the timing belt completely breaks, the engine can no longer operate properly and cannot be restarted. If the engine is an interference engine, the damage caused by a broken timing belt might be catastrophic, especially if the belt breaks while driving.

  1. Overheating engine

Overheating the engine is another major cause of why a running car abruptly stops without warning. There are numerous causes of overheating, but the most common is a lack of engine coolant or a problem with pumping coolant around the engine. A malfunctioning water pump, a snapped timing belt, or low pressure in the coolant system might cause a lack of coolant flow.

Symptoms of a faulty water pump include an overheated engine, leaking coolant, and steam emanating from the engine compartment. Coolant leaks can potentially create engine temperature concerns. Radiators, coolant hoses, a fractured coolant reservoir, and even the radiator cap frequently leak coolant. A faulty radiator cap might produce issues you are unaware of until it is too late. Symptoms of a defective radiator cap include an overheating engine, low coolant levels, ruptured radiator hoses, engine steam while driving, and coolant leaks.

  1. Bad spark plugs

Spark plugs are another essential component that permits your engine to generate power. They are the components responsible for igniting the air and fuel combination in the engine’s combustion chamber to produce combustion. Each cylinder has a spark plug of its own. With only one defective spark plug, you can still start your automobile and drive it. When many spark plugs misfire, though, your car may start, but it won’t likely last long. While driving, many faulty spark plugs will cause the engine to stall and shut down.

Before your engine totally dies and leaves you stranded, there are typically other warning indications you should be aware of, such as diminished engine performance, lack of acceleration, misfires, and a knocking sound when you turn on your car. If you have these symptoms, it’s simple to establish if you have a faulty spark plug; simply locate and inspect them. Once you can see your spark plugs with your own eyes, you can assess their condition. A defective spark plug is oftentimes blistered from excessive heat or coated with oil, fuel, or carbon substances.

  1. Faulty ignition switch

The ignition switch, which is located behind the ignition lock, is turned when the key is turned to start the vehicle. Numerous microscopic metal plates inside the ignition switch might develop rust over time. When this occurs, one of these plates may lose contact, causing the entire ignition to shut off. Or, if the ignition relay malfunctions, the system that regulates the quantity of electricity flowing through them will cease to function. These will result in an abrupt engine shutdown while driving.

Fortunately, it is relatively simple to determine if a defective ignition switch is the cause of your automobile shutting off while driving. Check the dashboard for any remaining lights when the vehicle is turned off. If the dashboard is inoperable, the ignition switch will likely be defective. After the car has shut off, place the keys back in the ignition and attempt spinning them. If this does not start the engine, there is likely a problem with the ignition.

Precautions you should take when your car shuts down unexpectedly 

Your car shutting off while driving could leave you stranded in the middle of nowhere or pose a safety risk if you are travelling at high speeds or on a highway with heavy traffic. Follow the procedures below to ensure your safety and the safety of other drivers on the road:

  1. Pull to the side to avoid causing a blockage or an accident

Try not to panic and steer your vehicle to the side of the road or the shoulder if your car shuts down while travelling. Pull over to prevent rear-end collisions with vehicles travelling at fast speeds as you’re coming to a stop on the highway. Be aware that your vehicle will lose the ability to steer and brake, but this is your only option. If slowing your car is too difficult, look for a safe area off the side of the road to use as a guide, and then apply the emergency brake. 

This will result in an abrupt stop, but it is far preferable to stalling out in the middle of the road. Then, you should move your vehicle safely away from the road and incoming traffic. If your car has died in the middle of the road, you should immediately contact us for assistance. You should only exit the vehicle if it is safe to do so.

  1. Try to restart your vehicle

Now that your vehicle is safely off the road, you must determine whether it can be restarted so you can at least drive to the nearest auto repair shop. If you’re fortunate and can determine or narrow down the cause, you may be able to restart your vehicle to be able to drive off.

  1. Turn on your emergency lights or place down a cone

If you cannot restart the car for any reason, you can use the emergency flashers or place down cones. This notifies other motorists that you cannot restart your vehicle and helps prevent merging into traffic. This should keep you safe while you determine your next move.

  1. Find or call people who can assist you

If you are unable to remedy the issue and your vehicle will not restart, you should contact roadside assistance. Check with your auto insurance provider to determine if this emergency service is included in your policy.

  1. Call for help or seek roadside assistance

Lastly, you can receive aid from roadside assistance services available 24/7. Utilize the emergency hotline and seek assistance. When your phone is malfunctioning, the police can also aid you in contacting roadside assistance. If your vehicle starts up again, you can drive home securely. Nevertheless, utilise an OBD2 scanner to determine if the engine control unit contains any error codes. This will ensure that proper diagnostics are conducted.


There are numerous potential causes for a car to stop working suddenly. These include a depleted gasoline tank, a malfunctioning crankshaft sensor, and a malfunctioning alternator. It is crucial not to panic and to walk to the side of the road and the nearest safe area if this occurs. A vehicle without a functional engine lacks power steering, making it significantly more challenging to turn the steering wheel. This also applies to the vehicle’s brakes.

Fortunately, engine failure while driving is uncommon, and it is mostly a rare occurrence. Modern automobiles feature diagnostic systems that determine what is wrong with the vehicle. Therefore, you should always begin your car diagnosis by reviewing the error codes first. As with the vast majority of car-related concerns, many of these problems can be avoided by performing routine maintenance and adhering to the manufacturer’s recommendations.

We hope you were able to acquire some helpful tidbits that would be of assistance if you ever find yourself in this situation. Remember to drive safely at all times!


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