BrandonSS

Alternator hasnt thrown any codes for low voltage since the first time I brought it in. I researched this code and many had it when their car sat on a dealership lot for a duration of time. Mine was a lease turn in so it sat on the auction lot and then the dealership lot for about a month. Many short trips, no extended run periods, etc were said to potentially throw the low voltage code from sitting and not allowing a full system recharge. Its been in the shop 3 times 2 for oil leaks and 2 times (1 was at the same time as the oil leak diag) for this shift lever error. The oil leak was timing cover and gasket behind the alternator. The past few times the only code has been for the Shift lever error. I even had the the BMW indy shop (Ress Motorworks) take a look into the alternator and they agreed with my forum findings. I also had the upcoming maintenance done while it was all apart (plugs, etc).

Ress suggested it could potentially be a faulty BCM, mechatronic, or even oil somewhere it shouldnt be within the trans/controller.

Thankfully I do have a warranty for the next 45k miles but I'm just frustrated with Dreyer and Reinbold's quick diagnosis, warranty the part and send it on its way opposed to looking into the situation further. I would love to let Ress take care of it for me, but we (warranty and I with deductible) have already paid $1280 to R&I the shift lever the first time.

BimmerFan52

I thought this code was continuing along with the transmission error. If the BMW shop measured the alternator output then the code wasn't truly reflecting alternator output.

I can see the battery discharge light on for a low battery charge, but once the engine is started and the alternator ramped up the alternator sets the system voltage unless the load on the system exceeds the alternator output and needs the additional current from the battery.

You are correct. Once you have paid, you have to stay like a dog on a pant leg until it is fixed right.