Strange battery behavior, randomly dies?

I'm wondering if anybody has experienced anything similar. Twice in the past month and a half, I have experienced the same exact thing. I approach the car, and try to unlock using the fob, without reaction. It doesn't unlock, but all of a sudden the alarm starts going off for about 15 seconds at 30 second intervals. Eventually, I unlock the door manually with the key. The little window up-down movement that is supposed to happen when you open the door doesn't happen. Inside, even putting the key fob into the ignition, there is no reaction or lighting up of the dash or anything. The car is completely dead, except for the alarm blaring even though the car is unlocked. Obviously, the car doesn't start.

The first time this happened was leaving work in the afetrnoon. In the morning there were no issues, and the temperature was about 40F which isn't very cold.

The second time, was this morning and the temperature was about 17F. Last night, again no issues. I jumped the car, and within 5-10 seconds of it starting, it died and I had to start it again. I also noticed that the RPM redline limiter which normally does a quick little movement to maximum and back to "cold" when you start the car, took like 10 seconds to do the exact same "movement".

The strange thing is that the past several days we had single digit temperatures as low as 2F and it was starting like a champ.

So, am I overthinking it, or do I need a new battery? I can't help but think the cold isn't the problem if this happened at 40F as well. For reference, I last changed the battery about 4-5 years ago if I remember correctly but I've never had to jump the car in the 6+ years I've owned it until now. I also remember my car clock running slow before I changed the old battery (apparently a sign of the battery needing replacement). Or could it be some connection? What could possibly drain the battery so much that even the dash doesn't light up when I unlock it?

I’m going to guess you haven’t had the battery cable replacement service by Bmw. It is a service bulletin they will do for free. Just take it to the dealer and have them replace the cable under the campaign. If you have had this cable replaced then I’m not sure .

Just be glad it hasn’t died while you are driving it

Remove your iphone USB cable from the center console.

msan wrote

I’m going to guess you haven’t had the battery cable replacement service by Bmw. It is a service bulletin they will do for free. Just take it to the dealer and have them replace the cable under the campaign. If you have had this cable replaced then I’m not sure .

Just be glad it hasn’t died while you are driving it

When was this bulletin issued? I'm wondering if it has been replaced. I've had all the recalls done but I don't remember anything about a battery cable. Unless this is not considered a recall?

It wasn’t technical a recall. More like a service bulletin. But they will fix for free

It died again this afternoon. Even with jumper cables it didn't start. I put in a new battery and still doesn't start. One small thing is that I couldn't figure out where this plug goes. Can anyone help? I must've unplugged it when removing the old battery but I can't for the life of me figure out where it goes now! But it should start even without this plugged in right??

Last time I will say it. It’s the cable by the fuse box behind your glove box. If you bang around there the car may come back to life. I’m trying to save you the headache of trouble shooting this but you aren’t listening.

I'm listening, and I will go get it done ASAP, however, as of yesterday the car isn't able to move. Unless BMW offers a complimentary tow to the dealership...

I decided to replace the battery anyway since it was 5+ years old, plus it was possible it wasn't holding a charge. Do you have any idea about this plug and where it goes?

sovietjet wrote

I'm listening, and I will go get it done ASAP, however, as of yesterday the car isn't able to move. Unless BMW offers a complimentary tow to the dealership...

I decided to replace the battery anyway since it was 5+ years old, plus it was possible it wasn't holding a charge. Do you have any idea about this plug and where it goes?

That looks like an aftermarket accessory wire. Don’t think it’s a normal wire.

msan wrote

That looks like an aftermarket accessory wire. Don’t think it’s a normal wire.

I was on the phone with BMW this morning, and they said this service bulletin cannot be done on my car unless my car's VIN has been assigned to be serviced with it. So it would not be free, and in fact they said I can't even have it done unless I have a notice sent to me to have it done. So...

Read this https://www.m3post.com/forums/showthread.php?t=1373697

msan wrote

Read this https://www.m3post.com/forums/showthread.php?t=1373697

I read the thread, and the various threads linked inside. After some digging around, it was in fact that cable behind the fusebox. The cable conection had some blackening on it, it was cleaned and reconnected. Now the car starts, although after a day outside it had to be jumped. Perhaps the NEW battery wasn't charged very well in the first place and the negative degree Chicago weather right now certainly isn't helping.

What's pissing me off the most, is that it looks like it is in fact the cable related to the service bulletin, but BMW refuse to fix it because I have a 2008 and the bulletin is supposed to be for 2009 and above

You can DIY . Fairly easy


https://www.m3post.com/forums/showthread.php?t=1357407&highlight=Cable

msan wrote

Last time I will say it. It’s the cable by the fuse box behind your glove box. If you bang around there the car may come back to life. I’m trying to save you the headache of trouble shooting this but you aren’t listening.

This...

sovietjet wrote

I'm listening, and I will go get it done ASAP, however, as of yesterday the car isn't able to move.

It's not moving or starting because the main battery power cable behind the glovebox isn't having a secure connection. Wiggle it and it'll fire right up, allowing you to drive or have it towed.

sovietjet wrote

One small thing is that I couldn't figure out where this plug goes.

That's for the factory battery kill switch used during shipping. Disregard it.

I appreciate all the feedback, I changed the cable. The issue with the car being dead like a brick is gone. However, now I have another problem. If the car isn't driven 2-3 days, especially now in the cold, it won't start. The dash lights up and everything but it won't crank because the battery is low.

Outside of something draining the battery while the car is off, could there be any other reason for this? It is a brand new battery.

sovietjet wrote

I appreciate all the feedback, I changed the cable. The issue with the car being dead like a brick is gone. However, now I have another problem. If the car isn't driven 2-3 days, especially now in the cold, it won't start. The dash lights up and everything but it won't crank because the battery is low.

Outside of something draining the battery while the car is off, could there be any other reason for this? It is a brand new battery.

So maybe you posted and I didn't see but how old is the battery?

Battery’s can be junk right off of the bat. Did you get a bmw battery or aftermarket. If aftermarket what was cold cranking amps. Is it a agm battery?

Jesus E90 M3 wrote

Remove your iphone USB cable from the center console.

Curious about this...does it draw even when the phone is NOT actually plugged in?

It is now summer and I had the opportunity for a little "test". I left the car for 5 days in the driveway while I was on a trip and wanted to see if it would start after I came back. The answer sadly is no. It unlocked, the dash lit up and all but it couldn't crank to life. I got the flickering dash as it was trying. I had to jump it. Driving it daily since then without problems but my clock is lagging a minute or two every day.

I did a quick battery drain check to the best of my ability. The car was off, and the key was out of the ignition (did NOT press the ON/START button). I checked the current through the battery and it was about 52-55mA, so just slightly higher than the recommended "normal" of 50 mA. I took it to Advance Auto Parts (where I bought this battery several months ago) and they did a battery check. I had been driving all afternoon and they measured 12.58V and 72% charge and said my battery was good. I can't help but think that can't be right...72% is good?

Yesterday I had a P157F check engine code and car in limp mode. Can't tell if this is related to the battery issues, but maybe?

To answer a previous question, yes the battery is aftermarket and AGM bought from Advance Auto Parts.

Is the best thing to do now just to go and change it again to a factory BMW battery at the dealership? It just seems like a huge waste to spend $600 to change a new battery with another one...

sovietjet wrote

I did a quick battery drain check to the best of my ability. The car was off, and the key was out of the ignition (did NOT press the ON/START button). I checked the current through the battery and it was about 52-55mA, so just slightly higher than the recommended "normal" of 50 mA. I took it to Advance Auto Parts (where I bought this battery several months ago) and they did a battery check. I had been driving all afternoon and they measured 12.58V and 72% charge and said my battery was good. I can't help but think that can't be right...72% is good?



Yesterday I had a P157F check engine code and car in limp mode. Can't tell if this is related to the battery issues, but maybe?

To answer a previous question, yes the battery is aftermarket and AGM bought from Advance Auto Parts.

Is the best thing to do now just to go and change it again to a factory BMW battery at the dealership? It just seems like a huge waste to spend $600 to change a new battery with another one...

P157F is a throttle activator error, hard to see how that relates to your issue of losing charge.

It's also hard to see how a parasitic draw of 55ma could be the cause of your problems, even though it is a little bit above typical. In 5 days of sitting you'd only have drawn 6.6 AH from a battery with a capacity of at least 80.

Anyway, you'd get the "Increased draw" warning light if you had a drain of over 80ma after the car has gone fully to sleep. The fact that you do not report this suggests that your problem almost has to be the battery.

If you went back to Advance with the battery, explained the test you did and asked for a replacement (not your money back), I'd bet they'd give it to you. I have a Platinum AGM from Advance - it's been flawless and (assuming it is not faulty) is obviously is a much better value than one from BMW.

Edit: Actually, before making any declarations, I should have asked you to describe exactly how you made the measurement of current draw

When was your alternator replaced?

I had a whole gang of electrical gremlins until finally the car died in the middle of an off ramp.....two days of straight troubleshooting, new battery, coding and service bulletin and bang the alternator was junk...

dpaul wrote

Edit: Actually, before making any declarations, I should have asked you to describe exactly how you made the measurement of current draw

I disconnected the negative cable from the battery in the trunk and then ran the multimeter in series (one multimeter cable touching battery terminal, the other multimeter cable touching the negative cable of the car) and measuring milliamperes. The car was off, key was out of range, and only the trunk was open. I waited about 5 minutes before starting this test.

Fooksdaddy wrote

When was your alternator replaced?

I've never replaced it. The car is a 2008 with 88k miles.