4x4 warning light in x3

[mikeAust]

My 4x4 warning light in my 2008 X3 2.0d has come on when starting the car. At slow speeds I can feel the stop skid working in my (steep) driveway but once on the road driving normally but the light remains on. It's not flashing. I didn't activate the 4x4 and holding the button for 3-5 seconds is not turning it off. It's a new issue for me after 220,000km. I've had next to no issues other than a fortnight ago had to have the turbo replaced courtesy of a crappy bearing. The battery was disconnected during that phase. Maybe just a coincidence. Any insights appreciated. Can see it is a recurring theme in the forum but can't find reference to this specific variant of the issue.
Update: actuator at fault in transmission, being fixed.

[gIzzE]

Once the battery was disconnected did you turn the steering wheel full lock in both directions before setting off, until you do this the 4x4 light will show on the dash. You are setting the steering angle.

[mikeAust]

Yes thanks tried that first (several times) as suggested by posts but after next drive got the full warning light triad! It's fixed now by independent mechanic.