5 Reasons Why Car Auto Start-Stop Not Working?

The start-stop system is critical to preserving the fuel economy and fuel efficiency of modern vehicles. When a stop-start system stops working, it is because the battery or the engine may overheat.

If you’re having issues with your start-stop system, I know a few ways to fix the most common issues. I can help you prevent them from happening later.

Why does auto start-stop not working?

Once only a part of hybrid cars, start-stop technology is now a part of most modern vehicles.

The system has many great advantages, like reducing emissions produced by gas-powered vehicles. Another reason car companies added start-stop systems to their cars is the system increases fuel efficiency.

Auto Start-Stop Not Working

So if you have a start-stop system in your vehicle, you should have more money!

Hybrid car owners are always able to avoid going to the gas station!

Now you can take all the money you’re saving from your start-stop system and use it to buy new underwear!

Yes, your wife told me and I am very disappointed in you!

But like any system, especially one in your car, you will come across the occasional issue from time to time.

So let me teach you about the different reasons why the auto start-stop system in your car stop working.

Reason #1 – There is an issue with the battery. 

auto start-stop battery

Start-stop systems need a special battery to run inside a car’s engine.

It is a special battery that allows these start-stop systems to constantly turn off and turn on again and stay idle. A regular battery just can’t do this. 

If you notice your start-stop system isn’t working, check if your check engine light is flashing on and off. If it is, you have to go to the mechanic and get your battery diagnosed.

You may be able to drive your vehicle without a functioning start-stop system. However, the fuel efficiency won’t be as good.

Reason #2 – The weather is too cold. 

start-stop system isn't working in snow

This is kind of funny when I learned about it because most people don’t want to work in cold weather. Now the systems in our vehicles don’t want to either!

You need to give your vehicle enough time to warm up in freezing cold weather. If you don’t, the start-stop system will not activate until the engine is at the right temperature.

You need to wait and let your car warm up until your computer dashboard signals to you that your start-stop system is ready.

You can drive your car if the weather is too cold for the start-stop system to activate.

However, your car will produce higher emissions. It also won’t perform as well with its fuel efficiency.

Reason #3 – You placed your car in a position and the computer’s start-stop system will not function while in that position. 

auto start-stop system

In certain car models, having your wheels turned at a sharp angle will override the start-stop system and your engine will not turn off.

The reason for this is based on what the computer system expects the driver to do. A car with its wheel placed in a hard angular turn will need to propel quickly to make a turn.

In this case, the start-stop system won’t activate so the car to pick up speed quickly

There’s nothing you can do to change the start-stop system in these types of situations. It is built into the computer system.

If you experiment, you can find the perfect angle degree turn. The wheels of your vehicle should be in the direction you want to turn, but your system will stay active.

But since this only happens at very angular turns, it won’t really be a big issue in your daily driving commute.

Reason #4 – You have your AC or heater on inside the vehicle at full blast.

AC or heater on inside the vehicle

Modern cars may be creations of engineering genius, but they’re not perfect. Every computer system does its best to preserve the battery.

So if you’re using the AC or the heater at full blast, it takes a lot of energy out of the battery.

So why are you trying to warm up or cool down the inside of your vehicle, the start-stop system won’t activate. There’s just not enough charge in the battery to fuel all these different functions. 

However, if you reduce the power of your heater or AC, then the system will activate. It’s all about to give and take. Hey, that reminds me of my wedding night!

Reason #5 – If you have a hybrid car, the start-stop system will not work if your battery isn’t fully charged.

hybrid car auto start-stop system

Yes, you read that correctly and I can’t say I’m not a little disappointed.

The start-stop system seems like a great way to save money at the gas station and reduce enough smog going into the air. But all these great advantages won’t appear unless my car is 100% fully charged?

That’s a major bummer, especially since I can’t always charge my hybrid vehicle.

In this situation, the only thing you can do is constantly keep your hybrid car charged up. Do this as much as to take advantage of the benefits of the start-stop system in your car.


So there are two reasons why your start-stop system may not be activating. The first reason is that there is an issue with the battery or with the central system. The second reason could be that it is a part of how the start-stop system functions.

If you want to learn a bit more about how the start-stop system in your personal car operates, read the manufacturer’s manual or guidebook. There should be a lot of useful information in the book. 

If you don’t have one, I don’t blame you. I don’t have mine either, just send an email over to the manufacturer and they can give you a PDF of your manual.

You can also send them questions about your start-stop system. Make sure to provide them with the make, model, and year of your vehicle.

  • Eric Williams

    I'm the founder of Daily Car Tips. I wrote articles in the automotive industry for more than 10 years, published in USA and Europe. I love sharing my knowledge and insights with fellow enthusiasts. Join me on this journey as we explore the exciting world of cars together!

    View all posts