Graph - High Side Pressure against Ambient Temperature
WARNING: This page is about a different car, the 2002 Jaguar XKR and 2002 Jaguar XK8. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Graph - High Side Pressure Against Ambient Temperature
Courtesy of JAGUAR CARS, INC.
The 'Normal' condition is that which is relevant to the prevailing ambient temperature.