Does a low battery can really causes trifecta ABS/DSC/Tyres Pressure lights?

[studio54]

Hi,

yesterday while driving my car showed up the famous three scary lights ABS/DSC/Tyres Pressures light, put engine off, back on, still lights.

I scanned with INPA, and got the worst scenario possible with codes 5FD0 and 5FD1.
(which average cost is a 2000$ repair at BMW dealer)

Didn't tried to erase codes yet.

i read on some cases, a low battery or dying battery can causes this phenomena, when plugged MHD to my car, i see that my voltage is :
11,73V when engine is off (this seems low?)
14,25V when engine is idling
(it's a AGM battery)

Could it be related ? (very small hope....)

Another thing is that i recently changed front brake pads at an indy shop, and noticed i get some pretty vibrations when braking hard from high speed.... does these vibrations could mess with something related to ABS/DSC ?

What things to do ??

I will try :

- to erase codes and see if it's persistent
- to check brake fluid level (seen some ppl said it can be related)
- to replace battery
- to take out the module and send it to repair center like ECUTESTING

any suggestions??

[studio54]

quick update: it's persistent, i erased code and then it came back immediatly

i wonder if it's a consequence of running my car with cowl filters (or no cowl)
like water or something ?

[Eyeman]

I tend to have frequent battery issues due to running a lightweight batteries. I have never had that code pop up.

[studio54]

after reading a lot of thread, i seriously doubt that it can be a battery related problem, moreover INPA shooted 5fd0 and 5fd1

i think i will inspect visually the DSC/ABS unit, and try to do things like unplug/replug the unit to see if it helps... if not, i will send it to get refurbished

any one know why these DSC/ABS unit fails in general ?

i thought it can be the water exposure due to running with no cowl, but it seems more to be the bad quality brush connector that connect pump and control unit.

i will update when i have more informations

[studio54]

Update: After doing some experimentations, i am now almost certain that my ABS/DSC unit problem is a stuck brush problem inside the pump motor.

I was able to make disappear the trifecta light by gently tapping the cylindric metal housing of the motor with a plastic hammer.

The problem is that lights came back after a moment of driving (understand brush are stucking again) and everytime during DSC is triggered on corner, WOT on slippery road which consolidate a stuck brush problem.

According to this video :

https://www.youtube.com/watch?v=6m2H-nC0CqE

The DIY repair seems not complicated, but is cleaning the brushes with alcohol (or other cleaner) is enough ?

Why brushes get stuck ? dust, dirt, or does it get simply worn over time?

Does some one here know if ECU repair compagnies (like ECUTesting and others) replace brushes connectors? or just clean it ?

[studio54]

Update:

I finally sent (80 EUR express shipping) the unit to repair at ecu.de for 426EUR
and made a brake fluid bleeding at an independant garage (they did it with INPA) for 100EUR.
So that' was a total of ~600 EUR for me.
(versus ~2000 EUR if i dealed with BMW dealer)