Most likely the DSC module might need rebuilding.

Also, it's good you checked your wheel speeds reporting on all 4 wheels. You also need to check you SAS to ensure logical values are being reported.

There are also some other routines you can check the functionality of the DSC. You can check the pump by running one of the routines. Sometimes that motor seizes up and you have to get a whole new DSC hydraulic block since it's not really "serviceable" to rebuild.

__________________
2003 BMW X5 3.0i -- MT5, 3.64s final gears, H&R lowering springs, K-Mac bushing kit
2007 BMW X3 3.0Si -- MT6