Why Your Car Shuts Off While Driving: Causes and Solutions

Car not starting is an annoying experience most of us have received our peak share. The worst of all is to have your car die while driving it on the highway or on a crowded street. This is a common experience for many drivers, which happens when least expected.

The common reason a car shuts off while driving and won’t start is a low fuel pressure caused by a weak fuel pump. However, several other things can be the culprit. The best solution is to diagnose the vehicle to pinpoint the exact problem and fix it.

In this article, I will explain these reasons, what to do if your car dies while driving and won’t start, and how to fix it. You will also learn what to do to minimize this situation from occurring.

What Would Cause a Car to Die While Driving And Not Start?

Several factors like low fuel, bad fuel pump, faulty car battery, and low charge alternator are the top reasons a car dies while driving and won’t start. Any of these issues will keep you stranded on the road.

Let’s examine these causes one by one.

Running Out Of Fuel

This might sound ridiculous, but it happens to many people. Drivers often forget to refuel their cars and run out of gas in the middle of the road. Another cause of this is when the fuel gauge is not giving the right reading. For instance, it shows you that you have a half tank of fuel remaining, but the tank is empty.

Bad Fuel Pump

A widespread cause for the car to die and won’t come on is if there is a problem with the fuel pump. In most cases, the car shuts off only when the car is hot and won’t come until it cools down.

The fuel pump is responsible for sending fuel from the fuel tank to the engine to complete the combustion process. The fuel delivered, however, should have a certain pressure as well as a certain flow rate. If the pressure or the flow rate is below the required level, the car will start stalling and eventually stops.

You may also have a problem with the fuel filter. The filter is attached to the fuel pump to purify the fuel before it enters the pump and the engine. It removes all impurities and stains which may block the fuel line and make the fuel not get to the engine.

Malfunctioned Ignition Switch

The ignition switch is the main gate that connects the current coming from the battery to the car accessories and starter motor for the car to start. If you have a problem with the ignition switch, your car might stall because the internal contacts are worn out. This leads to voltage loss due to heat and hard vibrations. Wearing out the ignition switch is common for high-mileage cars. This causes low-quality contact between two contacts.

Low Charge Alternator

When driving your car and the dashboard battery lamp suddenly turns on, it could be an indicator that the alternator is not charging the battery. If the battery runs down because it is not getting enough charge from the alternator, the vehicle will die and not start again until you jump or replace the battery. Plus, you’ll have to repair or replace the alternator to prevent this issue from happening again. This is true because the car battery relies on the alternator to stay charged.

Electricity is crucial for the engine to work. For instance, the spark plugs need electricity to produce a spark to complete the combustion. The operation of the fuel pump also relies on the electricity provided by the alternator.

Lousy Car Battery

A lousy car battery is a common issue facing several people because they think that the car only uses the battery for the first startup. This, however, is not true. When a car battery fails to work as it should or is in a bad shape, the alternator has to work harder to provide the required amount of voltage for the engine to move.

Running with a fatigued alternator causes the engine to encounter added stress, leading to frequent engine stalling. If your car dies while driving, won’t start, and just clicks, it could be you have a faulty battery.

Wrong Signal Sensors

In modern cars, several sensors are engaged in engine management. These car sensors keep record of the movements and instruct the ECU. The ECU responds then by sending signals to the designated actuators like spark plugs and injectors at a certain time and order.

In case the sensors are faulty, it could send ECU wrong readings about the engine’s status. This will then lead to wrong orders to the actuators, such as no sparkplug signal or no injector pulse. It eventually results in a bad performance, and a car shuts off while driving and won’t start.

What to Do If Your Vehicle Dies When You Are Driving

If you get yourself in this situation, your top priority is safety. Your safety and that of other road users are paramount. Once you are safe, make a quick check to look for clues on why this is happening. These tips may help you to get out of this situation safely:

Get the car out of the road or to the very right side of it. The first thing is to turn on the hazard lights to warn the oncoming cars that there is a problem with your vehicle. The steering may be very hard, but try your best to deal with it and use the handbrakes to park the vehicle since the normal brake pedal will not work as usual.

If there is a battery warning light on the dashboard, you have an issue with the battery charging system. It could be a problem with the alternator or the battery itself. Check the electrical systems, connectors, and terminals. If not, then check the drive belt and see if it is still connected. A broken drive belt can prevent the alternator from working.

If a broken belt is the root cause, it’ll prevent the alternator from working. As a result, the battery will run out of charge, and the engine will go off. To fix this problem, you must get a new belt and connect it to the engine pulleys.

Check for a clogged fuel filter if the car dies while driving but restarts again. It could also be a result of a weak fuel pump that can’t provide a standard pressure. Check the fuel pressure and do fuel lines check to track and diagnose the fault easily.

In case the car stops while driving, then start again after a while or after it has cooled down, it is a problem related to the engine management system or a faulty fuel pump. In this case, you need to examine the fuel pump. In most cases, all you need to address this issue is to replace the pump.

If that doesn’t resolve the problem, examine the crank position sensor since if it is faulty, it gives the wrong position for the crankshaft, which leads to a misfiring order making the engine stall.

How do we Minimize car dies while driving?

Nobody wants to get stranded in the middle of nowhere. But we often disregard some minor things that could save us from this headache.

We can minimize the chances of having our car die while driving by checking and cleaning the fuel filters regularly, ensuring our gas tank does not go less than a quarter, and replacing faulty components like the fuel pump when they start failing.

Components like fuel pumps do not fail suddenly. It usually has tale-tell signs before it fails completely. Always replace the fuel pump once it starts acting up when hot. If not, it’ll disappoint you one sunny afternoon.

How do you fix a car that randomly dies while driving?

As explained earlier, several factors can cause a car to randomly die while driving. The common causes include the fuel pump and ignition system components. This means you have to diagnose the vehicle to know the root cause of the problem. Here are two simplified methods to fix a car that dies randomly.

Method 1: Diagnose the vehicle

Get a scan tool, locate the OBDII diagnostic port underneath the steering wheel, and connect it. Now turn on the ignition and pull out the registered codes on the vehicle.

Some high-end diagnostic scan tool will tell you the error code, the meaning, and their possible causes. But if you have one of these cheap scan tools, you’ll have to search for the meaning of the code for your specific vehicle online.

Now you can go ahead and fix the problem. For instance, P0340, P0341, P0342, P0343, P0344, P0345, P0346, P0347, P0348, and P0349 trouble codes show there are malfunctions, incorrect readings, or no voltage on the camshaft position sensor.

If you receive any of these codes, the only feasible solutions could be to clean the cam position sensor, check and fix wire issues, or replace the sensor. In the same manner, if you receive other logged codes, find out the possible causes and address them.

Method 2: Check the fuel pressure

The truth is, the car computer does not check and store error codes for every single issue that happens in a vehicle. For instance, the car computer may not store trouble codes when the fuel pressure is below the required specification. However, low fuel pressure is one of the common reasons cars die while driving.

If the car diagnostic trouble code reader does not pull any code from the vehicle, test the fuel pressure and see if it is at the specified PSI. You can get Fuel pressure testers at affordable rates from Amazon, eBay, or your local car parts seller.

The fuel pressure should read between 40 to 46 PSI. If it’s below the specified PSI for your vehicle, you have issues with the fuel pump. Replace the pump with a new one rated for 46 PSI or the specified PSI for your car. If this doesn’t address the problem, contact your mechanic to run a proper diagnosis.

FAQs:

What would cause a car to just die while driving?

As explained earlier, several factors like a bad alternator, defective fuel pump, lousy car battery, no voltage from the camshaft position sensor or malfunctioning camshaft position sensor, and other fuel system and ignition issues can cause a car to die while driving.

When a car dies while driving, is it a battery or alternator?

If you have to jump-start your car every time and it keeps running, but it won’t start on its own without jump-starting it again, you have a dead battery that needs replacement. But if the engine starts but dies immediately, you probably have a bad alternator. The only solution would be to repair or replace the alternator.

What electrical problem causes the car to shut off while driving?

The car alternator is the powerhouse of all the electricity in a car. The alternator is responsible if an electrical problem causes your car to shut off while driving. If it becomes faulty while driving, the car will run on the battery power and shut off once the battery is out of electric juice.  It does not start the vehicle, but it helps recharge the battery and supply electric flow to electronic components in the vehicle.

Final Words

There are many reasons why a Car dies while driving and won’t start. Some of them will depend on the model of the car you are driving. However, the tips given in the above guidelines apply to almost all vehicles. To avoid or reduce the chance of getting into these situations, you are required to take some precautionary actions.

It is advisable to change the fuel filter as per the manufacturer’s recommendations. You also need to have the fuel in at least a quarter tank. This will increase the life of the pump and prevent clogging of the fuel filter. Always remember that safety comes first. If you have any vehicle failure issues on the road, always warn the cars behind you and get in the low-speed lane until you get the right help.