DSC 4x4 not activating
 

My 2005 X5 is not activating the DSC/4x4. How do you diagnose what the cause of it is? I know that the actuator which has plastic gears is often the problem, but how do you know without tearing in to it?

What leads you to believe that the DSC is not activating?

The DSC is normally always active, with all-wheel-drive (4x4) being the normal operational mode. The DSC will manage the torque to each wheel (via transfer case clutches and ABS modulation) under all conditions.

A failure of the DSC system (as detected by on-board diagnostics) is indicated by warning lights on the dash. Do you have any warning lights?

If the internal (plastic) gear in the transfer case has worn to the point of failure, you will often hear it clicking under the car a couple of seconds after shutting the car down (when the DSC system does a self-alignment, after every drive). The clicking sound is the worm gear on the actuator motor, skipping on the worn teeth of the plastic gear.

What he said.

What leads you to believe that the DSC is not activating?

The message on cluster that "DSC/4xr4 not activated"

Yep - that'll do it! :rolleyes:

Hard to diagnose fully without a full scan with BMW software (or a Foxwell etc.) - could be a simple steering angle sensor issue, a worn transfer case gear or an error in the ABS module (which is also the DSC module).

Try a simple calibration of the steering sensor (turn lock to lock a couple of times), then move to having a good listen to transfer case when shutting down the car...

Will do! Thanks!

Also, this car hydroplaned and hit those sand filled barrels. It dented the doors and left front fender, and broke the tie rod in the front, and the control arm in the back. Both the tie rod and the control have been replaced and it has been aligned, so it is tracking straight, the guys that aligned it are very meticulous. Maybe this info helps fill in the picture?

OK, so update, did the wheel side to side 3 x's, and then shut off the engine. Did not hear any noise, like clicking gears, and I got down ear level to underneath the car. 4x4 light is still on. I think it has something more to do with the wreck.

Left front fender side is where the ABS/DSC module lives...could be damaged.

Best to get it scanned and determine if it is reporting on the network--just like everyone is saying.

Got it, but you are talking about specialized BMW scanner, and not just an OBD 2 scanner, correct?

Correct. Need BMW grade scanner


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Probably coincidental and unrelated, but I had the 4x4 light come on not long after a wheel alignment with new tires. Ended up being the steering angle sensor that someone else mentioned. Cheap aftermarket part and fairly easy replacement if you can find the DIY that doesn’t require you to get under the car.

I did use INPA to confirm it was the angle sensor before replacement. Angle numbers would jump immediately to max (or was it min?) when turning one direction.

where is it located, bc I kind of have a feeling it got knocked around.

Abs unit is about a foot behind the left headlight. You need a BMW level scanner to read and module


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Steering angle sensor is about a foot below the steering wheel, around the steering column.

It just occured to me that the front fender damage has possibly taken out the ABS sensor cable on that corner... check the cable and sensor.

https://www.pelicanparts.com/techart...eplacement.htm