Dealing with the exact same issue. Buguyed, did you ever get this resolved? Alternator or faulty SAS?

I do not have a resolution as of yet but have checked/done these things since the last update:

-Checked voltage at the alternator, battery, and all applicable fuses (AT the fuse). Everything is normal. Therefore, I am ruling out the alternator for now.

-Had an indy try clearing the codes a couple times but didn't help.

-Just put on new tires and am going to get a front end alignment. It needs it (based on tire wear/cupping) and it might help the issue (ya right, but i can dream). I'd like to do this before I replace the SAS anyway, as a precaution.

-I've also read a little bit on the possibility of it being the Yaw sensor (located under the center console). These are $$ so i'm going the alignment and replace SAS first. IF this doesn't fix it, I'm just going to live with the stupid light being on. It's been on now nearly two years and I don't much care about it. The car is heavy with good tires, it does fine in the snow. :D

If you are experiencing the same issues and reach a conclusion before me, PLEASE POST!

My 4x4 light is on my 06 4.8. I did find my battery low staying at ~ 11 v. And I know the battery is weak, so I will be changing my battery next week. In addition I believe my steering wheel angle sensor either needs recalibration or replacement as my adaptive headlights does not move with steering.

Hey all.

Here are my notes of something similar.
http://www.xoutpost.com/bmw-sav-foru...al-solved.html

What I gather is that the DSC system uses inputs from a ton of sources however if you only have a 4x4 light and not all of the others then I would suggest you focus on yaw sensor, steering angle sensor, DSC model (on the valve block). The codes to BMW DSC are unique, meaning the generic code readers may not be a lot of help.

Gluck

Hi all, just reading this past post and I may have a problem. I turn on the 09 test and with the key on but not the engine running I get 11.6V. Start the engine and I get 13.3/13.4V. Shouldn’t I be getting 13.8V? Any comments appreciated. Maybe replace the battery first? I have been getting the dreaded 4x4 warning light come up every now and then. Seems moreso now. Checked for noise after switch off from under car to see if it was the transmission transfer gear but could not hear anything. Besides, I dont remeber getting the extra two warning lights of brake and abs (the 3 indicators).

regards
James

Oh, by the way it is a x5 e53 2005 4.4i v8. I am not sure if I have a water cooled or air cooled alternator.

Wow. You dug up an old one. Been awhile since I've dealt with this problem. Can't believe I'm still subscribed and got an email. I will say this. Your battery voltage is weak. But more so your alternator should be putting out closer to 14v running. Low voltage will make these vehicles do crazy things. Just first thought though I would lean towards alternator although I've had two E53's and never had an alternator go out. And I very well could be wrong but I think those were somehow cooled by your coolant system, atleast the v8's. And back in the day they weren't cheap. And if I recall those things are buried down towards the bottom of motor and not easy to get to. Wish you luck. But I would try to get a meter on your alternator and get a good voltage output reading and go from there. Also make sure your belts are good as worn belts can slip and not turn accessories fast enough to work properly. Tensioner pullies can get weak and cause belt slippage too. But again, the alternator should be putting out more voltage.

Yes, it is quiteold. Did a bit of a run today and the test 09 varies between 13.4 - 13.6. I think i am ok with that. Checked the battery after turn off and up to 12.4. So, I think I will try a battery first. I remember now, going away for 5 days a couple of times in previous years and would come back to find the battery dead. Also, I think the 4x4 warning light might be associated or its the steering wheel sensor. Will need tocheck that too. But, I would say the battery is on its last legs and not holding charge. $500AUD installed for a new one.

A strange thing happened this morning for a first. Was waiting at the lights and the car died. Turned the key, instrument lights, air con but nothing in turning over the engine. Waited a bit and tried again, nothing. Tried a third time and it started. Phew!! Has been running allday now.

Just wanted to add that my engine stopping at the lights was the MAF sensor (separate thread). My 4x4 warning light issue is still there. Would a faulty steering angle sensor show up on a scan?

Yes it would show up, but I only have a Foxwell NT-510 and Torque Pro so I don't know what code numbers would show up on other devices.

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