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BMW E60/E61 IBS (Intelligent Battery Sensor) Replacement on a Budget

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Here is an alternative to paying £200+ to BMW to replace your failed IBS (Intelligent Battery Sensor.) Many people disconnect their IBS when it fails, and that's fine if your battery is healthy and you use your car daily. But the IBS does a few important things including charging your battery accordingly to its age, and preserving charge when parked for long periods. Here is a step by step guide for diagnosing and replacing your IBS for around £20 instead of £200!


If you suspect your IBS has failed (eg your battery is going flat even if it is new) get your error codes read with INPA or similar. This is the code you will see if it has failed, 4477.




I think mine failed because water had dripped on it through the rear light cluster gasket, common fault on the E61. BMW updated the sensor at some point during the E60’s life, so you can no longer buy the original one I had. That means you need to buy the new style IBS and a converter loom which together cost over £200 from the dealer!

While looking for a used one on eBay I noticed that despite having many different part numbers for different cars including Mini's and other BMW models, all Intelligent Battery Sensors looked fundamentally the same. So I took a punt and bought this one for £20 from an E90 on eBay. Make sure you get the complete set - negative battery cable with IBS, AND the loom.




A few days later it arrived, and here it is next to my old one on the left (sorry for the crap photo, it was dark.) Notice that the IBS itself looks different, and also one of the connecting plugs is much bigger on the new one. This is why BMW sell you a converter loom.




Here’s a close up of the two sets of plugs next to each other. As you can see one plug is the same on the new loom, only one is different. This made me think that the converter loom was unnecessary, and as it’s only one wire (thick red one) I should just solder on the old plug.




This is the label on the new cable, note it mentions several different BMW models including the E90 and E70. It does not say E60, but I was sure it would work as I have seen lots of different ones all with different part numbers but for multiple cars. Just buy one that looks like the one in the photo above and you should be fine.




The two plugs chopped off so I can solder the old one (right) on to the new loom.




Here’s my new make-shift loom.




I put the battery back in, connected the new negative power cable (which is quite fiddly as the nut is behind some trim) and plugged in my new loom.




I cleared my error codes, went for a quick drive, read them again and as you can see, no errors! :D




I hope this guide helps other people with the same problem, and saves you some money. I know used parts are always a risk, but at a tenth of the price it will take quite a few failures to be more costly than buying one new sensor!

Edited by edd_jedi

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Seems straight forward and well worth considering, thanks for posting B).



Edited by DarkHorse

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Many thanks for the post I found it really useful as I am having issues with increased battery discharge constiantly every time I start the car now on an 520d msport touring 2008


i went to check the IBS to check I have he old style IBS but I cannot see any connectors on IBS seems they are all part of the harness


dkes anyone else have a IBS wothout connectors or am I looking in the wrong place?


In the top image there is a second module with a red flashing led does anyone know what this is for?




Edited by Savage678

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I recently had a problem with the air flow mass meter and the following fault appeared as well.


Intelligent battery sensor.   No communication (signal wire).  Is this the same as the topic discussed above?

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Power warnings on these cars are a bit of a minefield, it could be one or any combination of the below:


  • Old/weak battery
  • Broken or disconnected IBS
  • New battery that wasn't registered/coded correctly
  • Parasitic drain eg faulty MULF

I had all four of the above!

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Great money saving DIY thanks! 


There are some great maintenance and repair threads on the forum. It would be good to have them in some sort of 'library' but that's a big ask and not an expectation.  :lol:

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