Mazda Battery Management System Malfunction

The  Battery Management System Malfunction displays on the instrument cluster when the vehicle operating voltage drops below 12 volt due to a problem with the vehicle's charging system. 

 

Mazda battery management system malfucntion

This error message can come up from something as simple as keeping lights on or ignition on, but the engine is off. Doing this will discharge the battery below 12.4 volts which triggers the battery management system malfunction. If the vehicle starts, park it safely and let it run for at least 20 minutes. The alternator will charge the battery during this time, and the warning message will turn off the next time you restart the engine. While the battery is charging, remove any electrical devices plugged into the vehicle or take longer to charge the car battery. 

If the warning message doesn't turn off, further troubleshooting is required to determine what is wrong. Below we have listed some of the most common problems that can trigger this warning. 

Do not leave the vehicle unattended when charging the battery.

Symptoms

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

Possible Causes

Mazda battery management system malfunction

The most common problem that triggers battery management system malfunction on a Mazda is the age of the main battery, which may no longer hold a charge. Test the car battery using a battery 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 issues that can rigger 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 specs can lead to this error coming on. For example, installing a regular batter on a Mazda that requires a Q85 EFB battery. Or installing a battery that doesn't meet specifications. If your Mazda requires a battery with 850 CCA, but you install a battery with a 600 CCA capacity, you may end up with undesired errors. There are other specs such as AGM or lead-acid battery and battery capacity. Before purchasing a new battery for your Mazda, look up the battery specifications in the owner's manual. Or, if the battery in the car is the original battery, it will have the battery specs printed on top. Also, Mazda models equipped with iStop technology typically require EFB (Enhanced Flooded Battery) Battery. 
  • Bad Ground - A loose ground connection can also cause a battery management warning. The loose connection can be anywhere, so this won't be easy to track down. The first thing you should check is the ground connection between the engine and vehicle frame. 
  • Battery Terminals - Corroded or loose battery terminals can also trigger this warning. If you replace the battery and still get the battery management system malfunction, check to ensure the battery terminals are tight and do not move. 
  • i-ELOOP issues.  i-ELOOP uses a variable voltage alternator, large capacitor, and special DC-DC converter and performs three functions; 'regeneration,' 'storage' and 'use.' Conventional alternator charges at around 12 volts (V), however i-ELOOP's variable voltage alternator can vary its output voltage from 12 V to 25V in response to the voltage level of the capacitor and making it possible to supply electricity to the capacitor continually. Any of the components of i-ELOOP can fail. To troubleshoot this problem, codes must be read with a Mazda scanner. 
  • Short Trips - If you take frequent short trips, you cannot drive the vehicle long enough to charge the battery. The problem is most noticeable during cold weather because battery performance decreases as outside temperatures lower. Take a longer trip once a week or consider using a battery trickle charger. A 12 Volt Smart Car Battery Charger can fully charge the battery. For this, you will need a wall outlet. The battery will be charged at a low rate during this process, such as 3 Amperes, but this method ensures that the battery does not get damaged and can be charged to 100% capacity. 
  • PCM Software Issue - This error message can be due to a software issue. Contact your Mazda dealer to check if your vehicle has the latest software installed. If fault code P1794 - Capacitor Malfunction is present, you must carry out a PCM update first. In most cases, PCM updates will address this issue, and the error code can be cleared. 
  • Drive Belt (Serpentine) - A worn drive belt can cause this error message as well. As the drive belt ages, it starts to slip, causing problems with the alternator. Similar issues can happen on a new belt if you drive on water puddles. Water can splash and get to the drive belt, causing it to slip. As the drive belt slips, it will trigger charge system and iEloop errors. 

Frequently Asked Questions 

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

The deep cycle battery is used to run accessories and not start your engine; the Q85 starts the engine and idle-stop star.

Why do Mazdas require a Q85 EFB battery? 

Because Mazdas use the battery for the auto start/stop function. Q85 EFB batteries are the best for repetitive engine start / stop functions. Take a look at life cycles between wet, EFB, and AGM batteries.

Typical values.

Flooded (Wet Cell)

  • Maintenance: Maintenance Required
  • Type: Flooded
  • Cycle Life: 250-500 Cycles
  • Duty Cycle: 50% DOD
  • Typical Charging Voltage: 14.4-14.5 Volts

Enhanced Flooded Battery (EFB)

  • Maintenance: Maintenance Required
  • Type: Sealed Lead Acid (SLA)
  • Cycle Life: 500-1000 Cycles
  • Duty Cycle: 60% DOD
  • Typical Charging Voltage: 14.4-14.5 Volts

Absorbent Glass Mat (AGM)

  • Maintenance: Maintenance-Free
  • Type: Sealed Lead Acid (SLA)
  • Cycle Life: 400-600 Cycles
  • Duty Cycle: 80% DOD
  • Typical Charging Voltage: 14.7-14.8 Volts