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Can Automatic Cars Stall? The Details Explained

Close up of a woman driver holding her hand on an automatic gear shift stick while driving the car

When a car stalls, the first type people think of is a manual transmission. However, many people today have automatic vehicles instead of the traditional manual. If you are the owner of an automatic car, you might wonder – can automatic cars stall?

An automatic car can stall. Although rare, the trouble can happen due to the ignition system, fuel system, fuel pump, fuel sensor, control system, or engine pipes and hoses.

If you’re interested in learning more about stalling automatic cars, you’ve come to the right place. Read on to learn more about why automatic cars stop and if this process can damage your vehicle. The more you know, the faster you can address the issue if it comes to life in your car.

Why Do Automatic Cars Stall?

There are many reasons why an automatic car might stall. Some are minor, while others indicate a need for major repairs in your system. The more you know, the better prepared you can be if your automatic car stalls.

Here are the top reasons behind a stalled automatic car:

  • Ignition System Faults
  • Fuel System Trouble
  • Fuel Pump Failure
  • Broken Fuel Sensor System
  • Malfunction of Control System (ECU/TCM)
  • Deterioration of Engine Pipes And Hoses

Each provides varying damage.

Let’s dive into detail with each cause for a stalled automatic car. Each has a set of symptoms you can look out for to stop the event before it happens.

Close up shot of a man's hands holding a car's steering wheel driving safely in the city

Ignition System Faults

The first cause of an automatic car stalling usually happens quietly and without warning. Your car may suddenly sputter to a stop, leaving you shocked and confused. This quiet stall may be due to a failure in the ignition system.

An ignition system fault occurs because:

  • Spark plug fault: There is a spark plug issue that affects the rest of the system.
  • Failure to ignite: The spark plug does not ignite, which causes a spasm.
  • Fuel mixture stagnant: The mixture does not ignite, preventing energy from shifting to the engine in time for movement.

From that point, the engine will stall.

If you experience a silent stall, there is likely trouble with the ignition system. Take the car to a professional or get an experienced friend to examine it to confirm issues in the ignition system.

Mechanic repairing ignition coils close up of one removed on a gasoline engine

Fuel System Trouble

Another cause of automatic stalling might occur thanks to an error in the fuel system. This trouble is apparent if there is a slight vibration before it stalls. The whole car may shudder before the stop happens.

A fuel system issue happens because:

  • The system clogs: The fuel pump may be clogged, causing a blockage in the system.
  • Fuel falls behind: Fuel does not feed properly into the chamber, which prevents the engine from getting the energy it needs to operate.

A stall happens at this point.

If you feel the shudder, take your car to a professional or look at it yourself to ensure fuel flows into the chamber. A clog can cause tons of issues in the future.

Close up of a mechanic showing the fuel injectors on a rail inside the car's gasoline engine with the camshafts visible
Fuel injectors on a gasoline engine

Fuel Pump Failure

The fuel pump could be responsible for the engine stalling. This issue will be apparent if you head over a tall hill or round a steep corner. The engine will rattle and moan, then slow on the road.

A fuel pump failure happens because:

  • Contamination: Over time rust, dirt, and debris can all infiltrate the fuel pump and make it eventually fail. Typically a fuel filter prevents this but if that’s dirty enough it’s possible that the contaminants could reach the fuel pump.
  • Overheating: This typically happens when running low on fuel because the fuel pump isn’t sending enough fuel back to the engine which doesn’t allow the fuel components to cool down. It’s a good idea to avoid driving near “Empty” as much as possible.
  • Fuel pump gears: The typical gear rotor fuel pump has multiple components all working together inside a fuel pump. Over time these components can fail since there are quite a few moving parts. The only way to address this is to replace the fuel pump.

A stall occurs.

If you note errors when driving up or turning, take the car in. Fix the fuel pump as soon as possible for the best results on the road.

Automotive fuel system with the fuel pump locations highlighted in red circles diagram illustration
Most vehicles today have a fuel pump inside the gas tank. Some vehicles however have an inline fuel pump between the gas tank and the engine.

Broken Fuel Sensor System

A fuel sensor system breakage is another section of the car that could be responsible for a stall in an automatic vehicle. Note this error if you try to press the accelerator and the vehicle slides into a stall.

A broken fuel sensor system happens because:

  • Lack of proper measurement: The fuel system doesn’t measure the proper amount of fuel for the system.
  • Not enough fuel: As a result, there is not enough fuel in the engine to properly run.

The stall takes over the vehicle.

If you note constant stalling when you try to accelerate, you could have trouble with the fuel sensor system. Take the vehicle to a quality inspector to determine the fault as soon as possible.

Car fuel pump with the sensor built-in brand new isolated against a white background
Car fuel pump assembly with the fuel-level sensor

Malfunction of Control System

Another cause of stalling in an automatic car is a malfunction of the control system. You will notice this malfunction if the vehicle slows or grinds to a halt when you try to get it to stop.

Malfunction of a control system could happen because:

  • Air does not decrease: When you lift to stop acceleration, gas decreases, but the air doesn’t.
  • Ratio changes: The air-to-fuel ratio changes.
  • The ECU or TCM is defective: If the control module has failed, it’s possible that the physical symptoms can include stalling.
  • Ignition issues: The ECU is also responsible for the ignition system. If the coil packs and spark plugs check out including the wiring, there could be a circuit-level issue.
Car ECU ECM engine control module unit isolated against a white background
The engine control unit (ECU)

The stall fills the system.

Grinding in the engine is never ideal. Take your car in for repairs as soon as possible for the best results. If the engine control unit (ECU) or transmission control module (TCM) is defective, either get it refurbished or replace it.

Some vehicles only have one module controlling both the car engine and the transmission. Other vehicles have a separate module for each.

If you’re replacing the control module, most modules are VIN encoded, which will require a special OBDII scan tool to pair it to your vehicle.

Asian auto mechanic testing car ECU with a laptop

Deterioration of Engine Pipes And Hoses

The final cause could be the deterioration of pipes and hoses around the engine. You will hear an air leakage noise around the engine when you try to drive the car.

Deterioration of engine pipes and hoses happens because:

  • Cracks occur: Cracks appear in the engine pipes and hoses.
  • Extra air flows: Thanks to the breaks, additional air flows into the engine.
  • Ratio changes: The air-to-gas ratio shifts.

A stall locks in place.

Take your car to a professional to fix the pipes and hoses. Your vehicle needs them to thrive. Check the tubes often to prevent this trouble ahead of time.

Close up of a cracked rubber hose inside the car engine bay

Conclusion

It might seem like manual transmissions are the only cars that stall, but that’s not always the case. There are many reasons why an automatic car would stall, too. It could have faults with the ignition system, fuel system, fuel pump, fuel sensor, control system, or engine pipes and hoses. It’s more than possible for an automatic to stall.

We hope this information was helpful! The more you know, the better you can address the trouble if it appears. Take action and fix your automatic vehicle as soon as possible to prevent stalling in the car.

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References:

Car deal Page

AP Autocare

Reasons my Car is Stalling discussed by AP Autocare

Walbro Fuel Pumps

Why Fuel Pumps Fail

Ernest Martynyuk

An automotive enthusiast who's been tinkering with vehicles since I was 15-years old. Repairing automotive electronics has been my main job for over a decade now and have a passion for everything technical regarding cars.

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