Skip to main content
This article will discuss the BMW intelligent battery sensor, also known as the BMW IBS. We will explain what the IBS sensor does, common problems associated with the sensor, and how to troubleshoot IBS problems yourself.

Table of Contents

Symptoms of a Bad IBS Sensor

  • BMW battery will drain when parked
  • BMW will not go to "sleep," drains the battery
  • IBS not able to wake up the DME
  • Voltage fault, DME not on. This can be caused due to a short at the B+ line.
  • Voltage fault DME on, which can be caused to ground short
  • Dead car battery, the car won't start

What is BMW Intelligent Battery Sensor

bmw intelligent battery sensor

The BMW intelligent battery sensor is connected to the negative terminal of the battery.

BMW cars depend greatly on the battery not just for starting the engine but also for many other functions.

Battery plays a critical role in BMW cars. The Intelligent Battery Sensor (IBS) is used to monitor various battery parameters such as voltage, current, and temperature.


The IBS sensor is mounted on top of the battery negative terminal with a ground cable and two connectors.

One of the IBS cables connects gets power from the positive terminal. The second cable is connected to the DME and measures the battery load. This is known as the Bit Serial Data Interface or BSD.

BMW IBS sensor measures several battery parameters such as:

  • Terminal Voltage
  • Charging current
  • Discharge current
  • Battery Temperature
  • SoC (State of Charge)
  • SoH (State of Health

How to Troubleshoot BMW IBS Sensor

diagnose bmw ibs sensor with an obd2 scanner

To find out if the IBS sensor on BMW is defective, we scan the DME module for fault codes. You will need a BMW diagnostic scanner such as Foxwell NT510 for BMW

  1. Locate the OBD-II port under the dashboard, driver's side. 
  2. Plug your diagnostic scanner into the port. 
  3. Turn on the ignition but do not start the engine. 
  4. Turn on your scanner and allow it to communicate with the onboard diagnostic system. 
  5. Select your BMW make and model. 
  6. Go to Control Units. 
  7. Select DME from the menu. 
  8. Select read fault codes. 

Fault codes related to the IBS sensor are stored in the DME module. The DME will perform a check of the current, voltage, temperature.

These messages may be stored in the DME module if there is a problem with the IBS sensor. 

  • Voltage Fault
  • 299B DME Intelligent Battery Sensor
  • 002E8D DME: Intelligent Battery Sensor, signal transmission

How to check for IBS Sensor Recall

From time to time, BMW may recall vehicles if they have been manufactured with safety defects.

To find out if there is an IBS sensor recall on your BMW, you need to call the dealer and provide them with the VIN or check for recalls online. 

Check your BMW if it has IBS Sensor Recall online. 

How much does a new BMW IBS Sensor cost? 

A brand new BMW IBS sensor costs anywhere from $150 to $250, depending on the series. Search for  BMW IBS Sensor on eBay online. 

Can I bypass the IBS Sensor on a BMW? 

Disconnecting the IBS cable from the negative terminal will disable the IBS communication with DME. This is not a solution.

Bypassing the BMW IBS sensor is not recommended. If you bypass the IBS sensor, no information from the battery and its charge status will be available for the DME.

Additional Resources

  1. BMW TIS - Intelligent battery sensor_ E60, E61, E63, E64 Installation location Item Description.pdf
  2. BMW IBS “ Intelligent Battery Sensor “ What Is It, What Does It Do?
  3. BMW Intelligent Battery Sensor (IBS)