DTC P0620-01: Generator Control Circuit - General electrical failure: Action

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2015 Jaguar XKR-S, 2015 Jaguar XKR, 2014 Jaguar XKR-S, 2014 Jaguar XKR, and 2013 Jaguar XKR-S. However, it is still accessible from the selected car via links, so may be relevant.

Check for good/clean contact at generator B+ and battery terminal connectors
Refer to the appropriate electrical circuit wiring diagrams and check charging circuit for short circuit, open circuit
Clear DTC and repeat automated diagnostic procedure using the Jaguar Land Rover approved diagnostic equipment
If DTC remains, check and install a new generator as required. Refer to the warranty policy and procedures manual, or determine if any prior approval program is in operation, prior to the installation of a new module/component