Mazda i-stop System Malfunction (Do This To Fix)

i-stop system malfunction

The Mazda i-stop system is an innovative technology designed to enhance fuel efficiency and reduce harmful exhaust emissions. This engine start-stop system automatically stops the engine when the vehicle comes to a standstill and restarts it once the driver lifts their foot off the brake.

While the i-stop system offers numerous benefits, it can sometimes malfunction, resulting in various warning lights and issues.

In this article, we will explore the different aspects of the Mazda i-stop system, its common malfunctions, and possible solutions.

Overview of the Mazda i-stop System

The i-stop system is Mazda’s version of engine start-stop technology and is available in several Mazda models, including the Mazda 2, Mazda 3, Mazda 6, CX-3, CX-5, and MX-5. The primary benefits of the i-stop system include reduced fuel consumption and lower exhaust emissions. The system can be temporarily deactivated by pressing the i-stop OFF button, and it is automatically enabled upon each engine start.

Mazda i-stop Warning Lights

The Mazda i-stop system uses warning lights to convey its status to the driver. These lights include the amber i-stop warning light and the green i-stop indicator light. The following sections explain the meanings of these lights and the reasons they may illuminate.

Amber i-stop Light

The amber i-stop warning light will illuminate under the following conditions:

  • The system is deactivated by pressing the i-stop OFF button.
  • The bonnet/hood is opened.
  • The driver seat belt is removed, and the door is opened.

Amber i-stop Light Flashing

The amber/orange i-stop light will flash to indicate a fault with the system or a related component. This issue is often due to a battery that is failing to charge sufficiently.

Green i-stop Light

The green i-stop light will illuminate either when the engine has been stopped and turned off when the engine is restarted, or when engine idling stop conditions are met while the vehicle is being driven (European version).

Engine Does Not Stop

In some cases, the vehicle may come to a complete standstill, but the engine will continue to idle. Common reasons for this issue include:

  • The engine is not at optimum operating temperature.
  • The vehicle battery is not sufficiently charged, possibly due to frequent short trips. The battery charge threshold where i-stop is inhibited is typically between 75 to 80 percent charge or less.
  • The battery temperature is too cold (-5°C or below) or too hot (60°C or higher).
  • The air conditioner mode is set to the demist setting.
  • The air conditioning system is set to maximum heating or maximum cooling (A/C ON) position.
  • The engine will not stop if there’s a significant difference in temperature between the cabin temperature and the set temperature of the air conditioner.
  • Ambient temperature is extremely high or low.
  • When driving at higher altitudes, the atmospheric pressure is low.
  • The vehicle (automatic) has stopped on a steep incline.
  • The steering wheel is left at an angle and not in the straight-ahead position while the vehicle has stopped.
  • Engine stop does not take place when Mazda diesel versions are undergoing particulate matter removal from the filter (DPF regeneration).
  • Brake booster vacuum pressure reserve is too low.
  • Automatic gearbox oil temperature is too hot (118°C or above) or too cold (0°C or below).
  • For Mazda diesel versions, fuel injection amount learning is being performed. This process helps to improve many aspects, including fuel economy.

Engine Does Not Restart

In situations where the vehicle has come to a complete standstill, the engine has stopped but fails to restart. For safety reasons, the vehicle should be started using the normal method in these cases. The engine may not restart under the following conditions:

  • The bonnet/hood has been opened.
  • On certain versions, the driver’s seat belt is removed, and the driver’s door is opened.

Battery Management System Malfunction

The Battery Management System Malfunction message will display on the instrument cluster when the vehicle’s operating voltage drops below 12 volts due to a problem with the charging system. This issue can arise from simple situations such as leaving lights on or using the ignition with the engine off, discharging the battery below 12.4 volts, and triggering the battery management system malfunction.


Some common symptoms of a Battery Management System Malfunction include:

  • Battery Management System Malfunction
  • Master Malfunction Warning
  • Exclamation light and orange triangle
  • Engine auto start/stop is not working.
  • Charging System Malfunction. Stop the vehicle immediately in a safe place.
  • Engine System Malfunction (in some cases).

Possible Causes

Several issues can trigger a battery management system malfunction in a Mazda. The most common problem is the age of the main battery, which may no longer hold a charge. Test the car battery using a tester to determine if the battery is good or visit your local auto parts store to get the battery and charging system tested for free.

Other possible causes of a battery system warning on a Mazda include:

  • Alternator: A bad alternator is the second most common problem that triggers the battery management system warning.
  • Incorrect Battery: Installing a new battery that does not meet your Mazda’s specifications can lead to this error. For example, installing a regular battery on a Mazda that requires a Q85 EFB battery or a battery that doesn’t meet specifications can cause issues. Before purchasing a new battery for your Mazda, consult the owner’s manual or the original battery to determine the correct specifications. Mazda models equipped with iStop technology typically require an EFB (Enhanced Flooded Battery).
  • Bad Ground: A loose ground connection can also cause a battery management warning. The loose connection can be anywhere, making it difficult to track down. Check the ground connection between the engine and the vehicle frame.
  • Battery Terminals: Corroded or loose battery terminals can also trigger this warning. If you replace the battery and still receive the battery management system malfunction message, ensure the battery terminals are tight and do not move.
  • i-ELOOP issues: i-ELOOP is a Mazda technology that uses a variable voltage alternator, a large capacitor, and a special DC-DC converter to perform three functions: regeneration, storage, and use. Any component of the i-ELOOP system can fail, requiring diagnostic codes to be read with a Mazda scanner.
  • Short Trips: Frequent short trips can prevent the vehicle from being driven long enough to charge the battery, especially in cold weather when battery performance decreases. Consider taking longer weekly trips or using a battery trickle charger.
  • PCM Software Issue: A software issue may cause this error message. Contact your Mazda dealer to check if your vehicle has the latest software installed. If fault code P1794 – Capacitor Malfunction is present, a PCM update must be performed first.
  • Drive Belt (Serpentine): A worn drive belt can also cause this error message. As the drive belt ages, it may slip, causing problems with the alternator.

Read also >> Auxiliary Battery Malfunction: How To Fix? (Step by Step)

Read also >> Can You Leave a Battery Charger Connected? (Is It Safe?)

Frequently Asked Questions

How do I Know if I-stop is Working?

To know if the i-stop on your Mazda is working, you can look for the i-stop indicator light, which is green in color, on your dashboard. If the light is turned on, it means that i-stop is activated and working properly. However, if the i-stop light is not turning on or it is flashing, then it may indicate an issue with the system.

Factors such as battery level, temperature, and air conditioning settings can also impact the functionality of i-stop. If you are experiencing problems with i-stop, you can try pressing the i-stop button or checking the key fob battery.

If the issue persists, you may want to visit a Mazda dealership for further assistance. It is also worth noting that wedging a piece of paper into the i-stop button can disable it permanently, but this may render three buttons unusable

What is the difference between a deep cycle and a Q85 battery on a Mazda?

A deep cycle battery is designed to run accessories and does not start your engine, while a Q85 battery is used to start the engine and enable the idle-stop-start function.

Why do Mazdas require a Q85 EFB battery?

Mazdas require a Q85 EFB battery because they use the battery for the auto start/stop function, and Q85 EFB batteries are best suited for repetitive engine start/stop functions. EFB batteries have a longer cycle life and duty cycle compared to traditional flooded (wet cell) batteries.

Why is my Mazda start stop button flashing green?

If the push button start indicator light on your Mazda is flashing green, it means that the car is detecting your key and you should be able to start the car. However, if the car still won’t start, the first thing to check is the battery in the key fob. If the battery is low on power, try touching the key fob to the start button and see if the car starts.

If the problem persists, the key fob might be defective and not transmitting properly. It is recommended to try a second key fob to see if it happens with that one too. If the issue still persists, it is best to visit a dealership to diagnose the problem before getting stranded somewhere.

Does i-stop save fuel?

Yes, i-Stop technology is designed to save fuel by automatically turning off the engine when the vehicle comes to a stop, such as at a red light, and then quickly restarting it when the driver releases the brake pedal.

The amount of fuel saved can vary depending on the driving conditions, but engineers estimate it saves somewhere between 3-10% on average, with more fuel saved in stop-and-go traffic.

The i-Stop system also includes a fuel efficiency monitor that displays the i-stop operation status and cylinder operation status.

Can you turn off istop on Mazda permanently?

Yes, it is possible to turn off the i-stop function on a Mazda permanently. One way to do this is by pressing the i-stop button, as mentioned in the Mazda digital owner’s manual.

Another method is to wedge a piece of paper into the i-stop button, pressing it in permanently. However, the latter approach may have a drawback, as three of the buttons in the cluster would be rendered unusable.

If you are still experiencing issues with the start stop button flashing green, I would recommend checking the key fob battery and trying a second key fob. If the problem persists, it may be best to visit a Mazda dealership for further assistance.

Mazda i – Stop Initialize (Battery Initialize) >> Check out the video below:


The Mazda i-stop system is an advanced technology designed to improve fuel efficiency and reduce emissions, but it can sometimes experience malfunctions. Understanding the warning lights, common issues, and potential solutions can help you identify and address any problems with your Mazda’s i-stop system. If you encounter any persistent issues or warning lights, it is essential to consult a professional mechanic or an authorized Mazda repairer for a proper diagnosis and repair.

Steve P.

Steve is an automotive technician, technical writer, and Managing Editor. He has held a lifelong passion for cars, with a particular interest in cars like the Buick Riviera. Steve is based in Boise, Idaho.

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