BMW miss from bad battery?

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2013 328i convertible threw a battery discharge warning couple day ago so I figured a battery replacement was in order. Then last night, it started to miss heavily but I don't see any codes on my generic scan tool. I've replaced the battery this morning (kind of a pain since the AGM battery weighs a ton!) but the heavy miss remains. I need to order a BMW scanner so I can register the new battery so I'll have that in a few days to see if there are any BMW codes in there. The old battery was only at 11.7 volts so it was definitely going bad, but the car was still starting and running. It does have a "Service Engine Soon" message but all the on-board maintenance stuff shows green - not due yet. I understand this is a BMW unique message and is similar to a CEL but I can't tell what it may mean till my BMW scanner comes. (I think I'll order the Bavarian Technic 3 VIN setup so I can work on my Z4 as well)

Anybody know if a BMW will shut things down, like a fuel injector maybe, due to system errors caused by a low voltage battery? Seems like that would throw a generic OBD code wouldn't it? With the new battery, think whatever it is might clear with a few engine cycles?
 
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You would have to read the codes to know what is causing the misfire.

I have the Carly app and bluetooth adapter for my iPhone. It is a bit slow but makes reading the codes and changing features on the car pretty simple.
 
Yeah, I was looking at Carly but as I understand it, they have gone to a subscription model of $60 per year haven't they? Does that mean your app won't work at all unless you resubscribe and pay each year? I think the Bavarian Technic scanner provides free software updates with no charge so I figure it may actually be cheaper?
 
Yes, the Bavarian Technic tool is a much better option.

Personally, the best option is to buy the BimmerGeeks cable then download ISTA+ and BMW tools which can be found in the coding section of the BMW forums.

I mentioned Carly because you could probably get the adapter in a day from Amazon to figure out the issue with your car.
 
Most likely coil pack/packs failing, if your service engine soon light is on that means there are faults present. Id recommend doing them all if theyve never been done. Also check voltage while running and loaded up with accessories, like wipers full heat, defroster etc and make sure its above 13.5, but lower than 14.8 or 15. That foxwell tool looks pretty capable, and has alot of nice resets and live data, thats well worth the 200, it has features my professional level tool has. Also, if thats an early N20, the 4 cylinder turbo, check the VIN to see if there were any timing chain updates done. Alot of times the nicer ones that have lower mileage rarely ever see the dealer for updates and recalls.
 
Do you know for sure that Foxwell tool will register and code the battery? In looking at their literature, it's not clear to me that it will and I definitely need a tool to do that battery registration. I put in a 95 AH battery and took out a 90 AH so I'll need to re-code the system for the slightly larger battery... at least that's what I gather from reading on-line...
 
Solved!

So I decided to go for the Carly app to read the codes but Amazon Prime took till today to get the adapter to me :-(

It had all sorts of misfire codes, #2, #5, and even a code for "multiple cylinders" plus it had a bunch of other codes as well including "undervoltage". So I cleared everything, started it up and misfire cylinder #2 came back. All the other codes stayed off since the new battery was installed so that took care of all those. So I open it up and looked at the #2 spark plug and it wasn't fouled so I switched the coil packs between cylinders 1 & 2. Low and behold when I started it up, cylinder #1 misfire. So, down the the parts store for a new coil pack and all is well again. I did register the battery properly with the Carly app which works quite well by the way!

Bottom line was my battery for $150, the one coil pack replacement for $39 (Bosch OEM from Napa) plus $120 for the Carly diagnostics. So not too bad I guess...

Still wonder if the low voltage took out the coil pack? Anybody ever hear of that happening or is this just a coincidence the coil pack went bad the same time as the battery?
 
By the way, I'm pretty sure this coil pack is covered under warranty since this is an N51 engine and is covered under the 7 year/70,000 mile SULEV warranty. Anybody know if I can get reimbursed from BMW for the coil pack I replaced? How would I do that, just take the receipt into my BMW dealer? I bought this car used so I don't have a relationship with my local BMW dealer...yet!
 
Originally Posted by Scout1
By the way, I'm pretty sure this coil pack is covered under warranty since this is an N51 engine and is covered under the 7 year/70,000 mile SULEV warranty. Anybody know if I can get reimbursed from BMW for the coil pack I replaced? How would I do that, just take the receipt into my BMW dealer? I bought this car used so I don't have a relationship with my local BMW dealer...yet!

Call directly BMW North America, or if you have good relationship with Service advisor at local dealership, talk to them. Good relationship with SA goes long way. I save bunch of money on my X5 when my SCR cat failed. They did everything possible to save me from changing cat which was covered until 80k, and I had 87k.
Also, once you realized it is coil pack, why not taking it to dealer?
 
Originally Posted by meadows
Why do you register the battery in a BMW?

So the adaptive charging system knows the capacity of the battery.
 
Originally Posted by Scout1
By the way, I'm pretty sure this coil pack is covered under warranty since this is an N51 engine and is covered under the 7 year/70,000 mile SULEV warranty. Anybody know if I can get reimbursed from BMW for the coil pack I replaced? How would I do that, just take the receipt into my BMW dealer? I bought this car used so I don't have a relationship with my local BMW dealer...yet!


It's unlikely they'll reimburse for the coil for a variety of reasons, buy lesson learned.
 
Originally Posted by edyvw

Also, once you realized it is coil pack, why not taking it to dealer?


I thought about it, but I wasn't totally sure it was the coil pack till I replaced it and it fixed my problem. Also, I was worried about driving it with such a heavy miss thinking I would be dumping raw gas into my very expensive CATs. Come to find out that BMW engine management software actually turns off the gas to a cylinder where it detects a misfire so I probably would have been OK.
 
Originally Posted by dogememe
Originally Posted by meadows
Why do you register the battery in a BMW?

So the adaptive charging system knows the capacity of the battery.


Also so the system knows the battery is new since I guess it charges a new battery differently than an old battery...
 
Originally Posted by Scout1
Originally Posted by dogememe
Originally Posted by meadows
Why do you register the battery in a BMW?

So the adaptive charging system knows the capacity of the battery.


Also so the system knows the battery is new since I guess it charges a new battery differently than an old battery...


Yep. The system uses a chargine algorithm based upon the age and capacity. If you don't register the battery the system will overcharge the new battery which shortens battery life. Batteries typically last about 6 (+/-) years in a BMW.
 
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