Hi!

My car sometimes do random things ( airbag error, heavy steering, rough idle,seat heating or front driver door switch panel stop working) and i have a bunch of errors. I already replaced SGM and recode it, it was fine for a 200 km and now faulty again. I replaced lcm, and bsd with generator too.

My battery is in good condition
Those are my codes below. I will be very pleasured if anyone can help me with a little.
I have ncs,winkfp,inpa,tool32 and ista.


Error codes: error codes

Info codes: info codes



I tested the alternator. My battery goes 11.8-12.8 slowly after stop. After start, the voltage goes 14.2-14.5, but sometimes randomly drop to 13.1-13.2 (for example put in neutral while driving and clutch pushed, when turn on seat heating, when use side window switch.) and sometimes goes 14.8-14.9. And sometimes when voltage drops to near 13, my steering wheel goes hard, so i think it isnt normal, or?
Video from test at idle:

youtube video

Thanks in advance for any replies!

 

Sounds like a voltage regulator to me. At 11.8v when resting then it's around 30% charged and needs to be recharged or replaced. Your resting voltage should be 12.45-12.6. You may need to replace it. Get it tested and if bad replace it.

 

Thank you for reply! I already tested the battery. It is around 70-80% ,the dealer told me it is in good condition. OEM BMW AGM battery, 5 years old. Alternator are refurbished and voltage regulator are brand new. Any chance the new regulator is bad?

 

Yes I've seen new regulators be bad.

 

And I've seen brand new batteries be bad.