DTC U3001-94: Control Module Improper Shutdown - Unexpected operation: 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 datalogger signal - Main ECU Supply Voltage (0xDD02). Refer to the applicable System Wiring Diagram(s) and check the transmission control module power and ground circuits for open circuit, high resistance
Refer to the relevant service information and test the battery and charging system