DTC U0401-68: Invalid Data Received From ECM / PCM - Event information: Action

WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 2015 Jaguar XKR-S, 2015 Jaguar XKR, 2015 Jaguar XK, 2014 Jaguar XKR-S, and 2014 Jaguar XKR. However, it is still accessible from the selected car via links, so may be relevant.

Check the Engine Control Module for related DTCs and refer to the appropriate Diagnostic Trouble Code (DTC) Index information.
To confirm the repair and extinguish the warning lamps, clear the DTC, cycle the ignition state to off, then return the ignition state to on and wait up to 10 seconds