B12F4-12 Vehicle Speed Output - Circuit short to battery: Action

WARNING: This page is about a different car, the 2018 Jaguar XE and 2017 Jaguar XE. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: This DTC refers to a hardwired speed output from the body control module that can be used for aftermarket/accessory fitting where a pulse-width modulation speed signal is required. The circuit is not used on the standard vehicle, but required for aftermarket fit ment

Refer to the appropriate SYSTEM WIRING DIAGRAMS information and check the accessory road speed signal circuit for short circuit to power. Repair the wiring harness as necessary