Why Does My Car Shut Off? While Driving / When Stopped

Car shutting off while driving

Why does my car keep shutting off while driving?

The main reason why a car keeps shutting off while driving is because of a problem with the car’s fuel supply, or a fault power supply.

The most common reasons for a car shutting off are:

  • Low fuel
  • Crankshaft Position Sensor Not Working
  • Fuel Pump Not Working
  • Faulty Alternator/ECU

 

Low Fuel

At times, the fuel gauge meter on your car may not work properly and show that you have enough fuel for your trip. However, that may not be the case and you might have been running on low fuel, due to which your car can get shut off. Since checking this is the easiest, you should always start troubleshooting by checking for the fuel level in your car.

 

Crankshaft Position Sensor Not Working

This is a very serious concern that can cause the car engine to shut off while driving. It would not just stall the engine while driving, but also make the tachometer give erratic readings, reduce the fuel economy of your car, and might end up causing a misfire in your car’s engine.

 

Fuel Pump Not Working

If your car’s fuel pump is at fault, it will not provide your engine with the right amount of fuel consistently. It may pump the right amount of fuel for once and then the very next moment can shut the supply off if it is at fault. This can stop your car’s engine any time while driving.

 

Faulty Alternator/ECU

If the alternator in your car is bad, none of your car parts would receive electricity as they should. That could in turn lead to the engine getting shut off. In modern cars, a faulty ECU can also shut off power to the engine and turn your car off. The check light on your car’s dashboard will ideally detect if there is a fault with the ECU.

 

What Does it Mean if Your Car Starts and Then Shuts Off?

If your car shuts off after starting, it means there is a problem with your car’s ignition system. The car’s ignition requires the proper amount of fuel and air to keep your car running.

If there is a problem with either the fuel supply or air/vacuum supply, your car’s ignition system will fail and cause your car to shut off soon after driving or may not even cause the car to start.

 

Why is My Car Shutting Off When I Stop?

Your car can shut off while stopping if proper fuel is not received by the engine. This can occur if there is a problem with crankshaft sensor, vacuum sensor, or fuel pump.

Your car may also be intended to do this. As a fuel-saving strategy, most car makers have started installing the On/Off function in the newer cars, which shuts off the car when stopped. You can take the following steps to see if this is the problem and turn it off if needed.

  1. Check your car’s user manual to see if the Auto ON/OFF feature is there by default.
  2. If yes, check for the switch that can help to turn it off.
  3. If there is no switch, check for the procedure to turn it off. In most cars without the switch control, the same start button can help deactivate the auto ON/OFF feature.
  4. The ON/OFF feature will get activated again on every drive. So you have to stop it if you want each time you start a new drive.

If the issue is with the fuel supply, get your car’s codes checked by a technician.

 

Why is My Car Turning Off When I Turn?

A problem with the wiring or connectors around the steering shaft can cause your car to turn off while you try to turn the car.

If the car turns right back ON when the steering is straight, there can be a problem with the connector. If the car takes some time before starting back again, it is probably a loose wire.

There are hundreds of wires and connectors near the steering shaft and it can be difficult to identify the one causing trouble. You can follow the below steps to identify and fix it.

  1. Select one direction, left or right, and with the engine running, tug ON the harness around the steering and turn the wheel in the selected direction.
  2. When the engine stops, check for connections or wires that look pulled or worn out.
  3. You can move the harnesses one after the other to find the exact connector or wire that causes the engine to shut down.
  4. Once identified, tighten the wire or connector, or replace it if needed.

 

Why Does My Car Turn Off When I Brake?

A vacuum leak in the power brake booster is often the main reason why cars shut off on pressing the brakes.

Another reason why your car shuts off when you press the brakes can be a problem with the Idle Air Control valve.

Since brakes have nothing to do with how your engine runs, it has to be mostly a vacuum leak in the power brake booster. If it is a vacuum leak, you can perform a simple diagnostic test by following these steps.

  1. Access the brake booster and remove the hose connected to it.
  2. With the hose removed, press the brake pedal while the engine is on.
  3. If the engine doesn’t turn off, the issue is with the power brake booster and will require a technician to fix it.

 

Why Does My Car Turn Off When I Put it in Drive?

Your car can shut off when you put it in drive if there is a problem with any part of your car’s ignition system or fuel supply system.

Since there are many parts in a car’s ignition system and power supply system, a stepwise diagnosis is required to check what’s causing the car to shut and fix it. You can follow the sequence as suggested here to identify and fix the issue at the earliest.

  1. Check for low fuel
  2. Check for any leaks in the transmission system
  3. Check the wiring harness
  4. Check the Crankshaft position sensor
  5. Check the ECU and alternator

 

Why Does My Car Turn Off When I Put it in Reverse?

Problems with the idle air control valve can cause a car to shut off when put in reverse.

If it is plugged up, the engine will stall when moving into any particular gear (reverse in this case).

A problem with the power steering fluid can also cause the car to turn off when put in reverse. To diagnose your car for low power steering fluid, you can perform a simple test as explained below.

  1. With the engine on and the vehicle stalled, turn the vehicle to one side.
  2. If the engine stalls out while turning, it is the pressure control valve.
  3. If the engine does not stall out, there is a problem with the transmission of the power steering fluid.

 

Why Does My Car Turn Off When I Let Go of the Gas Pedal?

Problems with the idle control valve can usually cause a car to shut off when the gas pedal is released. The idle control valve decides the amount of air to be passed the engine when the gas pedal is pressed or left off.

If there is a problem with the idle control valve, a proper amount of gas will not be allowed into the engine, and the car will switch off on pressing or releasing the gas pedal.

To fix this, you can diagnose your car’s computer and check for the exact error codes.

 

Why Does My Car Turn Off When I Turn ON My AC?

Your car can turn off after you turn the AC ON if your car is on a low battery or there is a bad connection in your car’s power supply system.

The blower fan which turns on when you turn on your car’s AC draws a lot of current. That might cause a sudden drop in voltage in other parts of your car’s ignition system and cause it to shut off.

Fixing it will require a technician, but if the AC is not needed much, like in cold weather, you can disconnect it by either removing the AC Plug or unplugging the AC compressor.

 

Can Low Oil Cause a Car to Shut Off?

Yes, low oil can cause a car to shut off. The oil serves as lubrication for the metallic engine parts. If the car is low on oil and proper lubrication is not received by the engine parts, they grind against each other and end up stalling the car’s engine completely.

Regular checks for maintaining the oil level in your car is a must. If a car is driven on low oil, it can lead to irreparable damage to the engine and make buying a new car a better option than repairing your old car.

 

Can a Dead Battery Cause a Car to Die While Driving?

A dead battery can cause a car to drive roughly and can cause the car to shut off in rare cases if left unattended.

Batteries become dead over a period and do not die suddenly. If it happens due to a short in the wiring, the car will stop due to no power and may not start over again as there will be no power for the ignition system to create the starting spark.

 

Can Bad Spark Plugs Cause a Car to Shut Off While Driving?

Yes, a bad spark plug can cause the car to shut off while driving. If the spark plugs are bad, the engine may get stalled causing the car to shut off.

The spark plugs turn the fuel into fire to keep the car’s engine running.

While driving, a slight jerk can trigger the bad spark plug and stall the engine. To avoid that from happening, regular checks for the spark plugs are suggested when the car is taken for its routine maintenance check.

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