If you check the approved suppliers of cam shaft timing belts you will see they sell apart for the XF 3.0D so its safe to assume that these engines (AJD-V6/PSA) have belts and not chains. I have also seen forum entries (from Honest John) that indicate the replacement interval is 105K miles.
The X-Type Diesel does not have a cam belt, its a chain and never needs changing.
You dont it as timing chain
Cam Belt
chain
chain
chain
its a chain in petrol and a rubber belt in diesel
Chain
Both, timing belt from cam to diesel pump. Timing chain from cam to crankshaft.
The 2litre diesel used up to 2004 has a cam chain
no to both
no need it's chain driven