What does it mean when engine light amber color Restricted Performance comes on for a 2000 JX8?

Restricted Performance message on 2000 Jaguar XJ8 can either indicate a transmission issue or a low coolant level. To diagnose the problem, start by examining the engine coolant level. If the level is low, then address it accordingly. If the coolant level appears to be at the correct level, then use a diagnostic tool or take your vehicle to a qualified technician to have the transmission scanned for any fault codes.