DTC B100D-77: Column Lock Authorization - Commanded position not reachable: Action

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2018 Land Rover Range Rover, 2017 Land Rover Range Rover, 2016 Land Rover Range Rover, 2015 Land Rover Range Rover, and 2014 Land Rover Range Rover. However, it is still accessible from the selected car via links, so may be relevant.

Using JLR approved diagnostic equipment, check datalogger signal - Main ECU Voltage Supply (0xDD02). Refer to the relevant section of the service information and test the battery and charging system
Turn the steering wheel to ensure that the electric steering column lock mechanism is free to move and locking bolt is not restricted. Using JLR approved diagnostic equipment, clear the DTCs and retest
Using JLR approved diagnostic equipment, perform a CAN network integrity test. Refer to the appropriate system wiring diagrams and check the high speed CAN bus (body) circuit for short circuit to ground, short circuit to power, open circuit, high resistance
Using JLR approved diagnostic equipment, clear the DTCs. Perform routine - On Demand Self Test (0x0202). If the fault persists, install a new electric steering column lock control module and configure as a new module