[WilliamBMW]

So replaced my battery in my 2011 335i coupe about three weeks ago after I got the battery light on the dash and iDrive was indicating charging malfunction. Battery was old and I had just bought the car so I replaced it at a third party shop. They said they registered the battery after install and all was good. After a couple days the same error came up. I then automatically thought alternator. Had it checked at three different places and all three said the alternator was fine under a heavy load and still sending out about 14.2 volts. It seems when I drive at night and have the headlights on as well as cruise control and the A/C I get the error to come up again. I am thinking it is either an IBS issue and it needs to be swapped out or the voltage regulator. Anyone else experience this problem? I would rather change out the IBS instead of performing surgery on my alternator trying to swap out the voltage regulator.

[e91Owner]

Originally Posted by WilliamBMW

So replaced my battery in my 2011 335i coupe about three weeks ago after I got the battery light on the dash and iDrive was indicating charging malfunction. Battery was old and I had just bought the car so I replaced it at a third party shop. They said they registered the battery after install and all was good. After a couple days the same error came up. I then automatically thought alternator. Had it checked at three different places and all three said the alternator was fine under a heavy load and still sending out about 14.2 volts. It seems when I drive at night and have the headlights on as well as cruise control and the A/C I get the error to come up again. I am thinking it is either an IBS issue and it needs to be swapped out or the voltage regulator. Anyone else experience this problem? I would rather change out the IBS instead of performing surgery on my alternator trying to swap out the voltage regulator.

If it's putting out 14V when measured, without freeze frame data to see if it varies, it's hard to rule out the voltage regulator completely, but it's not likely. However, I have seen people many times, not connect all of the connections to their battery when reinstalling it. It may be worth looking in the compartment to see if they are all in place.

[WilliamBMW]

Originally Posted by e91Owner

If it's putting out 14V when measured, without freeze frame data to see if it varies, it's hard to rule out the voltage regulator completely, but it's not likely. However, I have seen people many times, not connect all of the connections to their battery when reinstalling it. It may be worth looking in the compartment to see if they are all in place.

I checked all the connections and they were all seated correctly. The reason I am thinking it is IBS is because the previous owner mentioned they had jumped the car from the battery and not the engine. I have seen a couple posts mention that this can fry the IBS which makes me wonder if that is what happened.

[gbalthrop]

Need THREE (3) Things to properly diagnose the issue:
1) All Fault Codes in DME Module Memory;
2) Freeze Frame Data related to those codes (which will be lost if codes are cleared);
3) You can read System Voltage (Alternator Charging as you Drive) using "Hidden Menu 9.00".

Hidden Menu must be "Reset" every time you turn on ignition, so it's a bit of a pain, but safer than trying to read a Scan Tool as you drive, as System Voltage is displayed on the Instrument Cluster:
https://www.carsaddiction.com/articl...er-hidden-menu

George

[carlover7]

Hello- hoping you can help.

The dealer says my E90 328I XDRIVE has some fault codes associate w/ the IBS. wants $215/ hr for a further diagnostic

dealer mssg-
FOUND FAULTS STOED FOR IBS CABLE - RECOMMEND DIAG.


how can i view fault codes? i do not have a scanner?

[e91Owner]

Originally Posted by carlover7

Hello- hoping you can help.

The dealer says my E90 328I XDRIVE has some fault codes associate w/ the IBS. wants $215/ hr for a further diagnostic

dealer mssg-
FOUND FAULTS STOED FOR IBS CABLE - RECOMMEND DIAG.


how can i view fault codes? i do not have a scanner?

If it something that is present on the CC-ID codes, you can look at the check control fault list.

Otherwise you'll need access to a scanner.