Intermittent CEL with p0347
 

Drove my 07 e70 4.8i wtih 29k mi with the battery voltage too low too long, I replaced the battery this week. But a CEL that I got before with the old battery has returned. It shows 2 instances of P0347, but goes away after driving it ~25 miles.

Right before my old battery conked out, I got a similar CEL with the starter would crank start the car then stall issue. It is strange that you can run the starter but not the other parts of the car with a battery at this state.

During the stall I got a P0118, P0335, P0343, P0347, and P0348, and the dash lit up like a XMas tree with the DCS light on, SES & Brake lights on in Red But I deleted all the codes and tried to start it again, and only this P0347 remained afterwards. Had it towed to the dealer, and they put a new battery, and now the CEL with P0347 is intermittent.

I google the P0347 code, but it is referring to the cam position sensor High Circuit A etc but I have not been able to find any exact answer. Other M62, N62 owners had all different issues, so it seems like it is a general fault code, so it is hard to pinpoint. People have replaced the CPS sensors and the CEL code came back.

Since the light just cleared itself again, I am hoping the car is still adjusting to the new battery and re-calibrating itself, and that the light won't come back on. It happened twice with the old battery but did not clear itself, I had to clear it with my scan tool, but with the new battery the CEL cleared itself.

Just thought I would throw this out here to see if anyone had a similar situation/help another owner down the road.

And yes lesson learned don't delay on things that need to be replaced ie. the battery...

Thanks in Advance!

When you replace a battery, you must "code" it to the car. In other words, tell the car the exact CCA of the new battery. I assume this can be done with GT1 but I know it can be done at a BMW dealer or with an Autologic. This is essential for any BMW newer than about 2006 or 2007. The car will NOT automatically adjust to the new battery.

Thanks
 

The new battery was purchased and installed at the BMW Dealer. They did code the new battery.

Thanks!

Agreed!
 

So coding/registration is for the car to know how old the battery is and charges it optimally to extend its life supposedly. But with short trips the alternator is too small to fully charge it, so what purpose does it really serve but to force us to take it in or learn how to code on our own. But not everyone has the time or savvy to do so!

I just got stuck buying another battery for my e90 from the BMW dealer today too! Grrrghhh!

That is not exactly correct. There is a "smart" battery control module which monitors the state of the battery- current going in, going out, voltage, etc. Once the battery starts to age the module sends more current and voltage to it so it can be at max charge every time. On ISTA I have seen as much as 15.7 volts in the system at idle, and as low as 14.2. if you install a new/different spec battery it will not destroy it in a day, not even in a year. It is RECOMMENDED to register the new battery, but not imperative.
Believe me, BMW is screwed by stealerships no less than the customers are screwed by them, but it is too late to go the Tesla way ;)

Well said! In America, everyone screws everybody, the American dream. That includes the wife. You have to be on your toes.:p: Check your alternator. One jump start can cook the regulator or the diodes in the alternator.

Does anyone keep their battery on a maintainer or charge it regularly with an external charger, please?

If not, why not?

Actually no. My wife is shorter than me.