Last week, I picked up a 2009 x5d, with pretty much every option on it other than the comfort access and sport packages. It has ~15k miles on it.
When I picked it up, the CA and I sat in the car for about an hour, with the key on, going through how everything works. Thereafter, it wouldn't start. The battery tested out good (original battery), so it was charged, and everything seemed fine for 5 days.
Over the weekend, I had a no-start condition again...I took the car into BMW yesterday, and they ran a battery of tests on it. The battery came up good again, and I spoke with service quite extensively. We ended up agreeing that the battery is likely bad, even though it was testing ok. Sitting on a dealer lot and not running can be very hard on batteries (I know this both from a previous life selling used cars, and a previous life working at a Sears Auto).
The interesting part is the fix. Rather than reinstalling a new lead-acid battery as the car originally came with, there was a TSB on a new battery. Those who are having problems with 2010 or earlier 2nd Gen X5s should pay attention. The new battery is an AGM battery that has greater CCA, greater reserve capacity, and greater resilience to repeated discharges. After the battery was installed, the ECM had to be reprogrammed, as apparently the charging profile for the battery is different, so the ECM now controls the alternator in a slightly different fashion. The dealer also mentioned that the reprogramming changes the profile for some of the features that consume energy (e.g. auto-lamps, pathway lighting, etc.).
The car cranks with noticeably more gusto now, and the battery problems seem to have been resolved. This might be a good thing for those having charging issues to look into...
01-18-2011, 01:04 PM
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