DSC/4X4 Disabled with codes

[Brads2002]

Any experts out there? Light comes on randomly with or without slipping the wheels. Sometimes after 30 seconds, sometimes its OK on a 3 hr drive. I would think its the common actuator gear stripping but I believe that would disengage 4wd. When my lights come on it feels like the 4wd is fully engaged similar leaving hubs locked on a truck. It doesn't like tight parking lot turns, almost skips the front wheels on pavement. In addition I don't have the odd noise at shutdown. I haven't pulled the gear to check but will be doing so shortly.

The codes i have are 5F3A (clutch open), 55C9 unsure but 4wd related, 5 & 9 steering angle sensor.

Alt voltage seems fine.

X5 is 2005 6-speed with 104K.

Thanks in advance for any guidance.