DTC U0001-88: High Speed CAN Communication Bus - Bus off: Action

Using the Jaguar Land Rover approved diagnostic equipment, perform a CAN network integrity test. Refer to the appropriate service information and check the high speed CAN bus (chassis) circuit for short circuit to ground, short circuit to power, open circuit, high resistance. Repair the wiring harness as necessary
If the fault persists, check other control modules for CAN faults. If only the rear differential control module is missing, install a new rear differential control module as necessary