[kanman64]

Good day everyone,

To be upfront, I am at my wits end with my 2009 335. So for a year and a half we have been chasing an electrical failure that caused the whole car to be dead, no interior lights, no dash lights and car would stall.

Initially at first we believed a bad CAS module was at fault and we had planned to clone a new one in as the mechanic believed it was the issue at fault due to CAS codes A01C and A0B4. I had to have it done at a different shop to my original tech passing away, with the new CAS in we didn’t have any issues for a week, but then the issue came back, ABS and DSC light would flash with the cluster going blank and the radio shutting off and back to no power. After purchasing an Autel so we could read our voltage in real time as we drove we saw consistent drops while idling and driving to under 12V so we had the alternator rebuilt with OEM Bosch internals, we have confirmed the rebuilt unit is charging the battery as we can see the SOC (State of Charge) getting to 100% almost everyday. However the issue remained, after reading up we came to the conclusion that our B+ cable and fusebox were at fault due to codes 2AB4 and 2DEC for power management. I replaced the main cable and fusebox and these codes have since cleared and to my knowledge have stayed cleared.

Now come to two days ago, I’m driving home and the cluster goes blank and DSC and ABS lights flash again and the car dies in the highway but comes back to life immediately. I turn off the radio and turn off the vents and AC and car makes it home no issue. My wife goes to start it in the morning, it powers up and immediately goes dead.

I know have High Voltage Codes stored in the ABS module but nothing in the DME in regards to voltage or power issues.

I am stuck as this car has been to three shops trying to figure this out and am at my breaking point mostly.

Any help would be appreciated.

[ctuna]

You would be better of going to the General section for this .
This subforum is mostly about Stereo .
Issues that effect the whole car are better handled on the General Forum.

I suppose you have checked the bottom of the battery storage area
for corrosion on the main hot power cables that go to the Engine compartment.
Also there was a recall on the power connector to the main power/fuse board in the cabin.
Also the ground cable between the Engine and chassis under the starter motor getting
corroded can cause some odd problems.

bmw boards and links
https://www.bimmerfest.com/forums/forumdisplay.php?f=99
https://www.e90post.com/forums/forumdisplay.php?f=27
https://www.e90post.com/forums/forumdisplay.php?f=2
https://www.e90post.com/forums/forumdisplay.php?f=122
https://www.e90post.com/forums/forumdisplay.php?f=368
https://bimmerretrofit.com/store/
https://www.e90post.com/forums/forumdisplay.php?f=197
https://www.e90post.com/forums/forumdisplay.php?f=378
https://www.e90post.com/forums/forumdisplay.php?f=16

There is much more expertise on this kind of problem on the general forum
Look for George over there.