4 Of Bad BMW Intelligent Battery Sensor Symptoms[Explained]

The BMWs these days come with an IBS sensor responsible for measuring and monitoring the battery performance. But many issues arise when this sensor doesn’t work as it should.

Can IBS sensors get faulty? Yes, BMW IBS sensors can get wrong and not usually function as they are supposed to. Due to this, the battery might drain, or there can be voltage faults.

There are a lot of other issues to deal with. I’ll be discussing some of the most common ones and the relevant fixes. Therefore, let us jump right into the article. 

What are the bad BMW intelligent battery sensor symptoms?

Some particular symptoms will help you realize the actual condition of your BMW IBS. 

These symptoms are exhibited mainly when the sensor has failed or is about to fail. Follow the section below to get an idea about those:

Battery Draining 

When the IBS has failed, it won’t identify most things. Either your battery is too old, or one of the electrical parts inside consumes power excessively. But that’s not the point of discussion. 

Whenever you see the issues relevant to draining the battery and the sensor not tracking it, it is evident that the sensor has failed. In this regard, rather than fixing, you must replace the sensor.

Dead Battery

Your BMW not starting means the battery is probably dead and needs replacement. That said, you did not get the warnings you were supposed to get, which means there was an IBS failure. 

Not identifying the mismatch of sensor signals and evident symptoms on your BMW will lead to such an issue.

Vehicle Not Starting

Another issue is that your BMW engine is not turning over. The outcome will be you not being able to start your vehicle.

It happens when the IBS falsely detects an irregular charging current and stops the operation from saving the battery. Eventually, the engine doesn’t tend to turn over despite cranking.

DME Not On

The DME in your BMW controls all the electrical functions and is a hub for all the electrical parts. But it won’t turn on if it doesn’t get a proper signal from the battery. 

Such issues are evident when there is an IBS failure in your BMW. The IBS not sending the signal from the battery makes the DME fail to respond.

Read Also: What Are BMW Footwell Module Failure Symptoms | What To Do

Why did the BMW IBS battery sensor go bad?

The primary function of the intelligent battery sensor in BMW is to monitor certain aspects relevant to battery health. It identifies things like voltages, temperatures, and the current levels of the battery.

However, this battery sensor can get faulty quickly due to its highly fragile nature. I’ll list some of the most common reasons below for your convenience.

Accumulation of Dirts

Not properly maintaining the components inside the vehicle often results in the accumulation of dust particles. 

It isn’t an issue for most car parts that would damage the part itself. However, for sensors or other electrical components, it can be harmful at times.

Returning to BMW’s intelligent battery sensor, the dust particles can turn the sensor bad and damage it permanently. Over the period,  when the surroundings of the battery and sensor aren’t serviced, this issue will arise.

Damages or Blows 

Since the IBS is super sensitive, any damage or accidental blows may harm it permanently. 

It can happen when any nearby parts are getting removed or checked. Also, during regular maintenance, unexpected blows may damage the sensor.

Battery Replacement

Replacing the battery may not cause the operations of the battery sensor to be problematic. 

But just like the previous problem, any blow while replacing or miswiring the sensor can make it dysfunctional.

Read Also: How To Bypass BMW Battery Safety Terminal? Explained!

How can you troubleshoot BMW’s intelligent battery sensor?

Troubleshooting would be the first resort if you want to solve the problem. In this regard, you would require an OBD-II device for diagnosis and need to follow a few steps consecutively. These steps are mentioned below:

  • Find the port for the OBD-II scanner, which will be under the dashboard on the driver’s side
  • After finding, plug-in the scanner into the port
  • Start the ignition without turning on the engine
  • Select the model and make of your BMW in the scanner
  • Navigate to the control unit and select DME
  • Look up into DME section and watch out for reading fault codes

If the scanner detects any fault code, it will show you the problem that must be resolved. 

Read Also: Bmw Battery Won’t Charge? Here’s What You Need To Know

What is the replacement cost of the BMW IBS sensor?

The replacement cost for BMW IBS varies depending on your BMW model and sensor manufacturer. Usually, it will incur something between $75-300. In addition, if you take mechanical assistance to replace the sensor, the cost would be around $35-110. 


The faulty IBS sensor in your BMW will invoke many things in your mind. I’ve listed down some of the most common queries that you might ask.

Where Is The BMW Intelligent Battery Sensor Located?

You’ll find the Intelligent battery sensor on the negative terminal of your BMW battery. To find the pathway toward the sensor, check the car’s manual.

What Happens When You Don’t Reprogram Your BMW Battery?

Your BMW battery is susceptible to failure when you don’t reprogram it. The battery becomes prone to draining, and it has a reduced lifespan. It can even cause a myriad of electrical problems in your BMW.

Can I Recall The IBS Sensor On BMW?

Yes, usually, it is possible but not recommended at all. By disconnecting the IBS from the negative terminal, you can do so, but it will eventually erase the change in the information status.

Is Disconnecting The Intelligent Battery Sensor Ok?

Disconnecting the intelligent battery sensor doesn’t automatically make it alright. But when there is frequent disruption of DME through multiple wakeups, one such disconnection can prevent this phenomenon and maintain battery voltage.


Bad IBS in your BMW means that you’re not getting an accurate picture of your battery health and condition. It is a glaring fact and can result in an untoward situation in the future.

Since this miniature device is sensitive, you must handle and maintain it cautiously. Regular monitoring might help you prevent issues resulting from bad IBS. 

That said, if your IBS replacement is inevitable, troubleshoot it first to confirm the problem.

In addition, the pricing of the IBS varies as per the BMW model. That is why check the information provided by the manufacturers very cautiously.

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