DTC U0001-81: High Speed CAN Communication Bus - Invalid serial data received: Action

Using the Jaguar Land Rover approved diagnostic equipment, check the snapshot data to determine the invalid data source control module. Check the relevant control module for related Diagnostic Trouble Code(s) and refer to the relevant DTC index
CAUTION: This procedure requires a minimum of Pathfinder 277 loaded or later
NOTE:
- This diagnostic step is only applicable to the L494/Range Rover Sport 18, 19, and 20 model year vehicles
- The Jaguar Land Rover (JLR) approved diagnostic equipment will read the VIN for the vehicle and automatically take the vehicle out of 'Transportation Mode' if required

Connect the JLR approved battery support unit
Connect the JLR approved diagnostic equipment to the vehicle and begin a new session
Follow the JLR approved diagnostic equipment prompts
Select 'ECU Diagnostics'
Select 'Powertrain Control Module (PCM)'
Select 'Update ECU'
Follow all on-screen instructions to complete the task
If required, reset the vehicle to 'Transportation Mode'
When all of the tasks are complete, exit the session
Disconnect the JLR approved diagnostic equipment and the JLR approved battery support unit