Just got my car back from the dealer and noticed that my AC/fan only operates up to the halfway point. It does not intensify past the halfway mark. The shop foreman at BMW told me that the battery is weak and the car has entered in to a safe mode sort of speak. The car has been giving weak starts, but cutting the fan intensity off at the halfway mark sounds BS ish. They did some sort of AC work while the car was in the shop last weak. Does this sound legit to anyone? He recommends me buying a $200+ battery, then reset the car for "new" battery (1 hr labor/$169). BT, the weak battery problem started after I got the car home from the shop. Anyone have similar probs with their AC/climate controls. Any help would be appreciated.

 

I had a weak battery issue in my 550i at 1 year old. I don't recall any climate control weirdness but had worse issues such as loosing the date/time or even an ABS failure light after one restart. I guess limiting fan speed is possible, and likely given the sophistication of the electronics.

They diagnosed my problem as a weak alternator and replaced it. The battery survived but I had to use a battery tender over 1 weeks time to get it back to 100%.

PS: If the battery is marginal, then a day in the shop could bring it to the surface and start causing problems... You could try the battery tender route to see if you can restore it to full but winter is always the toughest on batteries.

 

I've seen post where guys had additional problems such as error messages, but I only have the fan level problem. I guess I should replace the battery 1st. I might need one now since the car is an '04. I also need to confirm whether or not I can just change the battery out, without taking it to the dealer for a battery reset. Has anyone had any problems from simply replacing the battery on their own? Did the new battery die prematurely on anyone as a result?

 

My battery died three months after I bought my car 05 CPO of course.

They tried to charge $600 for a new one and they claim that if you buy an aftermarket battery the car will throw codes and idrive wont work. Many members on here have successfully changed batteries and have not reported any issues doing it.

 

I wonder if my fan speed will work properly if I replace the battery.

 

I do know that BMW has to reprogram the alternator to the proper charging level after replacing the battery. Otherwise it can throw codes.
A friend with a 645i just went thru that.

PS: A 4-5 year old battery may be due to be replaced.

 

I had the same issue, one night my fan speed was not going past the mid point. Next morning the battery was totally out, not sure how that happened, tried to jump the car didn't work. Later realized there is water in the battery area which froze over night and now the batter is stuck, my first thought was batter leaked, but after taking it out, ofcourse i some how had to break the ice vaccum the ice/water out. The battery didn't leak, so not sure where the water came from, but after i installed a new battery from Autozone, everything worked, the car threw codes for emission, but later were gone by itself. Yea the battery from autozone didn't have a discharge tube, not sure what the consequences will be but so far it been fine.