Tesla model Y Trailer harness 4 wire
Direct fit Tesla Model Y 4-Pin Trailer Harness. The lights will be activated but you will have a red trailer logo in the main screen indicating that the trailer mode has an error but all lights will work.
If trailer mode is not enabled, parking sensors will not be disabled while backing up and the autopilot will still work.
To activate the trailer mode, you need Tesla to change the configuration of your car but they will not do it if it is not their parts and installation. We are working on a module to activate the trailer mode. It'll be soon available.