E92 335 xDrive 2009 electrical problem

[ramonrebersak]

Hello.
From the last week have big problem with car electric.
So, here is what is going on:

Engine start, yellow exclamation mark was shown, same as 4x4 warrning on display. after a while, wipers turn on by itself, display power off, engine cooler power on (engine is completelly cold) and if I try to put it in reverse, it is ok but after that if turn it into drive it knock pretty hard, same as it change from 1st to 2nd gear (like no oil in gearbox symptom). Logically it is in safe mode.
So, was connect Delphi (dont have impa) and was clear all errors from all available modules. Turn it off, start engine, same things happen. Now, I turn wheel full left then full right and 4x4 on display dissapear same as exclamation mark for all errors. After turn it to drive position and take over 10kmh it light up all things I mentioned above and gearbox on changing from 1st to 2nd again knock.
Battery is new and also registered to car (as I have that option on Delphi). Wasnt have any problems with car so far.
Any idea or help is appreciated.
Thank You

[dankatz]

A very common problem is the rusted ground cable. Google it. It often causes electrical problems that make no sense. It is an easy fix and should be checked under the hood

[dankatz]

Something like this

https://www.m3post.com/forums/showth...a%2013mm%20nut.