DTC U0001-87: High Speed CAN Communication Bus - Missing message: Action

WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 2017 Jaguar XJR, 2017 Jaguar XJ, 2016 Jaguar XJR, 2016 Jaguar XJ, and 2015 Jaguar XJR. However, it is still accessible from the selected car via links, so may be relevant.

Using the Jaguar Land Rover approved diagnostic equipment, check the snapshot data to determine the missing message source control module. Refer to the electrical circuit diagrams and check the relevant control module power and ground circuits for open circuit, high resistance. Repair the wiring harness as necessary
Using the Jaguar Land Rover approved diagnostic equipment, perform a CAN network integrity test. Refer to the electrical circuit diagrams and check the high speed CAN bus (powertrain) circuit for short circuit to ground, short circuit to power, open circuit, high resistance. Repair the wiring harness as necessary
Using the Jaguar Land Rover approved diagnostic equipment, check the snapshot data to determine the missing message source control module. Check the relevant control module for related DTCs and refer to the relevant DTC index