4x4 warning light on for two days solid now

[RenoHuskerDu]

Hi all,

The 4x4 warning light came on yesterday and despite my strong language and hurled invective, it persists. HDC is also inop, and the Traction Control button has no effect, as if it were stuck on.

I poked around here a bit and only found this one about the problem. Its resolution doesn't help me though.
http://xdrivers.co.uk/forum/index.php/t ... l#msg53356

However there is a bit more on Xoutpost so I resuscitated an aged thread there.  I'm just rattling this Xdrivers cage as well in case one of you has a suggestion, being deeper thinkers in general than the yanks (I am allowed to say that as I was born in California).

I tried turning the steering wheel full lock left/right/left but that did not help. From http://www.xoutpost.com/bmw-sav-forums/ ... ost1069761 it would appear that the suspects are 1) wheel sensors, 2) steering angle sensor, 3) yaw sensor, or 4) plastic worm gear nicked in the transfer case.  I did just have the handbrakes rebuilt by my indy who may perchance have damaged a wheel sensor back there.

So now I really need to read codes. I have no reader but have heard that this functionality is now available for android. This intrigues me so if anyone has been down that road please share how it went. And of course where you purchased the necessary interconnect cable from the car to the android.

Cheers,

[X5Sport]

Is this My Carly plug in OBD2 wifi dongle what you are on about?

I have the IOS version and it seems to work.  You can even send the codes to them for checking. 

[RenoHuskerDu]

Yes that dongle would float my boat were I to also purchase the app:
https://play.google.com/store/apps/deta ... Full&hl=en

Cheers for that! The adapter is available directly from the app vendor. See what I meant about yanks?

[Horizon]

I've got the Carly app and wifi adapter as I'm also on Apple, you would use the Bluetooth adapter on Android.
Not sure if you can recalibrate the steering angle sensor with it though , has your indie got INPA, that may be more usefull if it's the SAS.
Carly app is good though, several coding options with it too.

[RenoHuskerDu]

I get a new symptom now. Whilst reversing and turning sharply, I feet the transfer case tighten up, the 4 wheel drive activating.  This tends to support the idea that it is a wheel sensor at fault.  Inaccurate wheel speed data is being sent to the calculator, which decides to send torque to the front axle. It seems difficult to imagine how the SAS or yaw sensor could produce this symptom.

I'm ordering that Carly pack you recommended.

[RenoHuskerDu]

I finally got this sorted out so I'm reporting back to the forum.

It was the pesky SAS at fault.  All other sensors check out fine. My Indy re-calibrated the SAS and the system came back to normal. But I had one intermittent failure since, so I'm having him order a new SAS and he'll install it soon.

His experience is that the SAS is most often at fault. He does not see many wheel sensors fail unless clumsy home repair work has damaged them physically. He's never seen the yaw sensor fail so far.

If anyone reading needs a good Indy in the Belfort (90) area, PM me for contact info.  He does not speak English but I could give you a hand with that.

HTH