Gear Ratio Monitoring
WARNING: This page is about a different car, the 2005 Jaguar XJR, 2005 Jaguar XJ8, 2004 Jaguar XJR, and 2004 Jaguar XJ8. However, it is still accessible from the selected car via links, so may be relevant.
The gear ratio diagnostic checks that each gear ratio is correctly engaged. Also, following a gear shift the diagnostic checks that the transmission has engaged the target gear within the allowed time.