2016 BMW F15 X5 Electrical Drain / Battery Discharge

[theothermp3]

For some reason, my '16 X5 xDrive35i gas 6cyl has been killing its own battery over and over for the past several days. Started seemingly out of nowhere, and I can't seem to identify why this vehicle has decided to do this. A little history here: last year around the same time give or take a month, my car started doing the same thing. Started with "increased battery discharge when stopped" warning on the dash, and eventually I found the car stone dead. Now, I don't drive it too often, maybe once every 3 or 4 days - but still well within the realm of acceptable idle time.

At that time, the battery was about 5 years old, so I got the battery changed out which seemed to fix the problem. A week later, the issue was back, so it went back to the shop. They replaced the auxiliary battery as well as they said that would also drain the main battery. Was fine for a little while, then the issue happened again. Back to the shop we go, and they run a full electrical diagnosis, energy management test, the works. They found that multiple circuits were staying active after the vehicle had shut off, but they didn't indicate what specifically.

So they did a full software update on the car. Factory reset all of the modules and basically started from scratch. Once they did that, they indicated there were no consumers remaining active during the followup energy management test. It seemed like this fixed the issue and I was free and clear. Now here we are about 9 months later, and the issue is somehow back again. Car went entire spring, summer and fall without any issues. I have another (probably very expensive) diagnostic appointment at the dealer next week.

How is this stuff troubleshot? In the olden days when things were somewhat simple, you could troubleshoot draw pretty simply using an ammeter and pulling fuses. Not sure if there is some better way to figure out what module or system could be remaining active when the car is in rest mode. I find it suspicious that the last time this happened, it was during the cold months, and now here we are getting into the height of winter again and the issue has resurfaced, although I don't know how that could correlate. At face value, it doesn't seem like the car is leaving anything on, at least nothing is obvious (water pump running noises, leds on for hours, etc.)

I attached the fault codes I pulled from the car with my scanner today when I jumped it, not sure if there is anything there of value that anyone with a better technical BMW brain than me can make sense of.

[Ozzyman]

Did you ever find the solution to this? Mine is behaving identically...

[virtualbong]

I thought I had found gold by finding this thread in my search result but no luck. I am having the same issue and the dealership charged me the replacement of both my batteries ($1,000+!) and then it died again. I jump started it and it worked and would work if I pretty much drive every day but I didn't end up driving the car yesterday and it's dead today. I checked the battery and it's at ~11.6V so something is draining it after one day of idle time. I checked all outlets and the only thing was a usb cord connected but not plugged into any device. At the same time, my damn harmon kardon amplifier died so I need to fix that too. I am thinking I charge up this bad boy and trade it in...ugh...I just paid the car off this month too but electrical issues are no joke and can be really costly.

[virtualbong]

I am also finding that it may be a faulty IBS sensor that could be draining the battery so I may just get that replaced on my own and then have the dealership re-register the batteries.

[FREE100KSECRET]

Interesting subject.

I have had the same mystery drain and on the hybrid it is evidently even more critical as it sets off dozens of codes related to low battery voltage issues. So I changed out 12V battery and registered it and it helped, but because I don't use the F15 X5 40E that much, the hybrid battery drains when not in use. I understand that the hybrid battery actually charges up the 12V, so not sure if this is related, and very few similar issues were found online.

Given I use to drive every day, never noticed the hybrid draining without use. It charges up fully, so that would indicate it is still healthy as I understand, so something appears to be draining it, and the 12V battery eventually over a few days. After clearing all the low voltage error codes, I have four which will not delete and keep coming back. These codes appear to be unrelated, strange as I saw it, but these hybrids are a whole new ballgame to me.

P18BB, P1ACF, P18FD, P123B, P2721 which are EGS issues generally and a short fault. So using a little common sense, these would drain batteries. When I see the word short it is a clear sign something is no right. Given the terminal distribution unit on top of 12V battery has several fuses in it, not typical replacement fuses, I suspect this is an issue as it controls power to critical components, as well as shuts down power to some when you leave vehicle. So I ordered a new one and will post if it cured battery drain issues.

[FREE100KSECRET]

I checked and changed out the battery terminal distribution and no change.

[alpctek]

I'm having the same issue. Did anyone find a solution? This is crazy. I have to pull my positive post when I park for the day or the battery will drain. I can hear something humming under the hood. I've changed the battery and had BMW register it.

[Tomcat_F15_STL]

Originally Posted by alpctek

I'm having the same issue. Did anyone find a solution? This is crazy. I have to pull my positive post when I park for the day or the battery will drain. I can hear something humming under the hood. I've changed the battery and had BMW register it.

Water pump failure. Replace it & thermostat & Mickey Mouse flange & hoses.

You will be good.

[joealanda]

I’m having the same issue, replace water pump and thermostat, same headache. Replaced IBS and still causing problems.
My new battery is less than 2 years bought it from BMW dealer. Only in winter time. Hope someone solved this problem, it seems it’s common issue for many bimmers.

[virtualbong]

Originally Posted by Tomcat_F15_STL

Water pump failure. Replace it & thermostat & Mickey Mouse flange & hoses.

You will be good.

I asked my service advisor to check the water pump but they wouldn't just go ahead and fix it without a thorough diagnostic check. $600 later...guess what, the water pump was failing. Replaced and everything works great now.

[virtualbong]

Originally Posted by joealanda

I’m having the same issue, replace water pump and thermostat, same headache. Replaced IBS and still causing problems.
My new battery is less than 2 years bought it from BMW dealer. Only in winter time. Hope someone solved this problem, it seems it’s common issue for many bimmers.

Another possibility is if you have comfort access...one of the handles may be failing and drawing from the battery when the car is off.

[sgrimshaw]

Thought I found gold here too. Same under hood hum as alpctek here. Replaced battery but had to exit quickly for almighty youth sports. Car ended up dead just a few hours later. Thinking IBS because one of it's jobs, if I understand correctly, is to preserve the battery for one more start in the event of high drain. Days of confusion, wife getting grumpy...help!

[mattdk318i]

https://www.bimmerfest.com/threads/n...ttery.1400098/

My wifes X5 is doing the same, i think im going to see if the pump runs after its cooled off and locked. If so im going to pull the water pump fuse. IF this fixes the over night drain im going with a pump replacement.

[BMWLugnut]

Same issue. Replaced wife’s X5 battery yesterday…dead today. Looks as though the water pump is a recurring theme. Any luck with the new one? Where did you buy the part

[stocktree]

Originally Posted by BMWLugnut

Same issue. Replaced wife’s X5 battery yesterday…dead today. Looks as though the water pump is a recurring theme. Any luck with the new one? Where did you buy the part

When the car is off and cool, open the coolant cap and see if you see A stream of coolant? The water pump is pretty quiet, and hard to hear.

[tinlittle]

Originally Posted by stocktree

When the car is off and cool, open the coolant cap and see if you see A stream of coolant? The water pump is pretty quiet, and hard to hear.

"A stream of coolant"? Did you mean if the water pump is running (while it is not supposed to be), there'd be visible coolant movement on the surface?

[stocktree]

Originally Posted by tinlittle

"A stream of coolant"? Did you mean if the water pump is running (while it is not supposed to be), there'd be visible coolant movement on the surface?

If you remove the reservoir cap, and look inside, you'll see a little stream of coolant from the side, shooting towards middle. Just below where the cap would sit. If you don't notice anything, then the pump is probably not on.

[imkazaam]

Originally Posted by virtualbong

Another possibility is if you have comfort access...one of the handles may be failing and drawing from the battery when the car is off.

Thanks for this suggestion, how can I confirm this?

[virtualbong]

Originally Posted by imkazaam

Thanks for this suggestion, how can I confirm this?

I am not sure if there is a way for anyone to confirm this without taking it to the dealership for testing. The only potential warning sign is if one of your comfort access handles is not working as it should be. That was one of the issues I had been having and the service advisor said that sometimes the comfort access is malfunctioning and drawing power by continually checking for your key fob close by. If you have not experienced any issues with your comfort access then I doubt that would be it.