If you’re driving and your car shuts off while you’re driving, this can be alarming. When the engine turns off while the car is driving, this is also known as stalling. In most cases, this happens when your vehicle is decelerating or when the engines RPM are lower – this is likely to be whilst you’re idle and not whilst you’re accelerating.
When you’re at a stop light, you could feel the vehicle jerk and the engine dies. If you’re a new drier, this can be alarming and if you’re in the middle of the road, having a vehicle that stops can annoy other drivers and this can cause some anxiety.
Is the Check Engine Light On?
The first thing that you should notice when your car turns off is that the check engine light comes on. The car’s computer (EGU) controls the emissions control system and if it notices that the ECS is having problems controlling or regulating a problem, the check engine light will come on. When the check engine light is on, it’ll send an error code to the EGU and when this error code is diagnosed, it will reveal what’s wrong in your car.
To diagnose the error code when the check engine light comes on, you’ll need a professional 0BD2 diagnostics tool (View on amazon). A professional diagnostics tool will allow you to find out the error codes meaning – this will allow you to know what’s going on within the car that’s causing it to turn off while you’re driving. If you’re using a diagnostics tool that’s standard, you’ll have to look up the error code online or on the service manual.
If you don’t see the check engine light come on, you can look below to see the most common reasons why your car will shut off while you’re driving at a lower RPM. If you’re in special circumstances, like your vehicle is particularly hot that day, or cold, you’ll need to take this into consideration when you’re diagnosing the problem.
Faulty Fuel Pump Relay
The fuel pump relay is an electrical component that’s activated when the ignition is turned on – its main purpose is to provide and maintain a consistent voltage supply to the fuel pump. If there are any signs of weakness within the fuel pump relay, the engine is going to suffer with it. Therefore, if the fuel pump relay is faulty, this will directly show within the engine. If the fuel pump relay isn’t allowing enough fuel to the combustion chamber, the engine will turn off. The engine needs to run on the right air-fuel mixture, sometimes can run on a mixture that’s too rich but if the mixture of fuel is inadequate, the engine could turn off while you’re idle. If your fuel pump or fuel pump relay is bad, there’s nothing you can do about it, you’ll just have to get it replaced.
Another thing that could be faulty is a clogged fuel filter. This fuel filter is meant to clean the fuel that goes into the engine – if the fuel filter is clogged with debris, new fuel that’s going through the fuel filter won’t be able to go through the filter so it’ll go straight into the engine. If bad fuel is getting into the engine, it could cause the engine to shut down.
If the fuel supply lines break or get clogged, the fuel that’s being transferred to the engine might start to leak. The supply lines need to be fully intact for the fuel to get to the engine – if not, the engine can shut off while you’re driving.
Empty Fuel Tank
If your fuel tank is empty, then no fuel will be sent to the PCM by the fuel pump and there will be no fuel for the air-fuel mixture. If there’s no fuel, the spark plugs won’t be able to ignite just air in the cylinders so your engine will shut off. If you’ve been driving for a while and you can see that your fuel tank is running on E, it’s a huge sign that the engine has shut off because there isn’t any fuel left. If you didn’t know that your fuel was running on E due to a bad fuel gauge, you’ll need to get your fuel gauge checked out. If you haven’t filled up your fuel tank in a long time and your fuel gauge isn’t indicating this, you’ll need to check it out.
Faulty ECU
Most new cars have an ECU fitted to them and this a module that directs various car functions. It looks over a lot of systems with the main one being the emission control system and it checks to see if there are any issues within them that can’t be maintained or regulated. If this system isn’t working, a lot of systems are going to fail since they need the ECU. If the ECU is faulty, then your car can lose power. If you notice that your check engine light is on, this could indicate that the ECU is faulty. If the check engine light comes on because of a bad ECU, you’ll need to get to the local workshop as soon as possible because this can cause further issues with your vehicle. If you want to make sure that the ECU is faulty, you can use a diagnostics tool.
Faulty Alternator
The alternator controls the supply of electricity that goes to your vehicle. If the alternator isn’t providing the right supply, then the car can shut off while you’re driving. There are various components that need a power supply in order to function and if the alternator isn’t providing electricity to these vital components, you’ll notice that the car turns off. If it’s specifically the alternator, you’ll see the lights in your car turn off as well. If you’ve been driving for a while, you may start to notice your alternator going bad – If you notice that your lights keep coming on and off, it could be because it’s receiving an intermittent power supply. Alternators are electrical components so they can be repaired or replaced easily – its best to go to your local mechanic to get this checked out.
Faulty Ignition
The vehicle’s ignition gives power to the engine. If there’s a problem with the ignition, your engine could stop working and turn off while you’re driving. When your car turns off, you should try turning the car on again and if it doesn’t turn on, it could be a problem with the ignition system. Your vehicle has an ignition relay that controls the amount of energy that goes through them – this isn’t as bad as a faulty ignition system, but the relay is important to the ignition system. Relays only have a certain life and if you’ve been driving for a while, it’s inevitable that the relay is going to fail. You should go to a local workshop if you sense that the ignition is bad.
How to Fix a Dying Engine
If your engine is dying while you’re driving, this is a sign that it’s in poor condition. Failing to maintain your engine over a period of time can cause it to die and this can lead to a blown engine. Maintaining parts of your car will ensure that you don’t have problems so if you’re experiencing them, it’s a sign that you’re about to spend a lot of money at the dealership.
If you want to avoid engine problems or other issues and save $100s of dollars that you’ll spend at the auto repair shop, you’ll need to service your vehicle often – you can use our mechanic-rated Auto Maintenance and Repair Manual to do this. It’s basically what mechanics use to go through your vehicle to check if there are any problems that need fixing. As soon as they notice the most minor problem, they’ll ask you to fork out some money even though it’s a problem you can fix yourself in minutes – the manual will teach you how to maintain your vehicle every few thousand miles and it’ll teach you how to fix minor problems that mechanics will ask you to pay for; saving you money in the long run.
A lot of our readers have the Auto Maintenance and Repair Manual printed on their garage wall and 92% of them haven’t visited the auto repair shop in the last year because they know what to do to avoid problems. All it takes is giving your vehicle a little attention every few thousand miles and you’ll never spend money at the workshop again.
What to Check If Car Shuts Off In Specific Situations
There are specific situations that your vehicle could turn off in. These situations will allow you to narrow down the problem so you can see why your car could be shutting off while your driving. You should remember what happens when your car stops. For example, when it shuts off, where it shuts off, and what shuts off with it. Remember these situations will allow you to diagnose what’s causing your engine to turn off.
Cars Shuts Off After Only Being on For a Few Minutes
If you start your car and you notice that it stalls only after you’ve driven for a few minutes, there are a few components you’ll need to check for. When this happens, it could be down to a:
- faulty ignition coil
- bad ignition module
- faulty crankshaft position sensor
- bad fuel pump motor
Electronics within the position sensor, fuel pump, ignition coil and ignition module can develop problems that won’t come to light unless the components are warmed up and the wires expand causing the fault to appear. If you want to test for an open coil in any of these components, you can do so by:
Removing the sensor or coil from the car.
- Use a multi meter (View on Amazon) to test the resistance of the ignition coil.
- Compare this with the resistance it should have got in the repair manual.
- Heat the sensor up by using the sun or a dryer then test the resistance again.
- If the readings are different, then you need to replace that component.
Car Shuts Off When You Reach Stop Light
If your car turns off when you reach the stop light, this means that you were driving at a low RPM. This could indicate that the idle air control solenoid is bad. The ECU uses the IAC to bypass the throttle valve, so more air car be injected. If there’s a problem with the IAV valve or air passages in the throttle, for example, fuel varnish build-up, carbon, or dirt, this could stop air going through the air ports – if air can’t go through the air ports, then the car could stop when the engine is idle. To check if the IAC is clogged up with any of the things mentioned above, you need to inspect it.
- Find the IAC around the throttle body.
- Unplug the IAC solenoid connector.
- Remove the solenoid from the throttle body.
- Check the air passages for any build air that could stop air from getting through. If you find anything, make sure to clean them. If the passages aren’t clogged, it could be that the IAC motor has failed.
- Remove the IAC from the throttle.
- Connect the IAC solenoid to a battery power – you can do this with a jumper box and cables. If the IAC solenoid doesn’t respond, you’ll need to get it replaced.
Car Shuts Off with Lights
If your car shuts off while driving along with the lights, this can lead to serious problems because lights also provide a lot of safety. For example, you could have driven over a bump or take a sharp turn and the radio along with the lights and engine turns off. In most cases, everything should start working again after a few minutes. There are a few things that you can check when you notice this happen.
- Start the engine and let it idle.
- Open the engine hood.
- Slightly move the battery cables if your car has one.
- If the engine shuts off along with the lights when you do this, the battery cables could be damaged which is messing up the connection.
What to Do If Cat Shuts Off While Drive
If your car stalls when you’re driving, this can be a big safety problem. In this situation, you should be looking out for your safety and the safety of other cars. Make sure not to panic as it can make you do things worse if you’re on the highway.
Pull Over – the first thing you need to do if you find your engine turning off is to restart the car and pull over. Or, your car could still have some power behind it and it’s able to be steered into the side of the road. If you panic whilst doing this, you’re going to struggle even more. If you’re unable to slow down your car, then you should drive to a safe place and use the emergency brake.
Restart Car – once you’re at the side of the road, then you can restart your car. If your car is able to turn on again, then there might a been a slight problem with the ignition, but it could also mean that the problem was minor. If your cars unable to turn on, you’ll need to get an on-demand service to take it to the mechanic.
Emergency flashers – the next thing you need to do is let drivers know about your situation. The best way to do this is to turn on the emergency flashers. These are specific lights that let other drivers know that there’s a problem with your vehicle. This means that they will avoid you ensuring that your safe and to avoid any collisions.
Call Emergency Mechanic – you need to call an emergency service that could check your car out there and then to see why it didn’t turn back on after shutting off. If it can’t be fixed there, it’ll be towed somewhere else to be fixed.