If a 2021 Land Rover owner reports intermittent battery drain and the dealer finds B1D9F11 in the BPM event log, the fix is not replacing the battery but reflashing the DDM via JLR’s PATHFINDER 2.0, then performing a LIN bus initialization routine.
This code often does not trigger a Check Engine Light or a warning on the dashboard. Functionality: land rover b1d9f11 2021