DTC B129F-13: Function LED - Semi-Automatic Advanced Parallel Park - Circuit open: 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.

Refer to appropriate system wiring diagrams and check the parallel park LED circuit for open circuit, high resistance. Repair or install a new wiring harness as necessary
Using JLR approved diagnostic equipment, clear the DTCs and perform routine - On Demand Self Test (0x0202). If the problem persists, suspect the switch/LED