Special Programs Not Available, Terrain Response - System Fault FIXED in 5 mins. LR3 / Discovery 3

Steering Angle Sensor Calibration - On this Land Rover Discovery 3 (LR3) I had a system fault come up when driving away, saying 'System Fault, Special Programs Not Available' and it wouldn't let me raise or lower the suspension, nor would it select any of the Terrain Response settings.
I've fixed this in just a few minutes using a GAP IID diagnostics tool.