DTC B1C43-23: Master Interior Light Switch - Signal stuck low: Action

NOTE: To validate the repair firstly run the engine for 120 seconds and check the interior light switch function, then use the Jaguar Land Rover approved diagnostic equipment to check this DTC is no longer set within the body control module

Refer to the electrical circuit diagrams and check the interior lamp switch signal circuit for short circuit to ground. Repair the wiring harness as necessary
Check the operation of the interior lamp switch. Rectify as necessary