2004 Jaguar s type dsc and parking brake along with engine system fault comes on and car goes into limp mode when slowing down or when it rains.
I had the same thing here, I paid lots of money to find out what is the problem, mechanics played with my poor car damaged everything they can to stop it from running, but when I found out that when I changed the battery on my own, with a turkish manufactured battery of 100 A big battery, not even the fault stopped appearing but all the car was boosted in performance, Dsc not available and Park Brake is all related to the level of electricity running the parts of car was screaming back to you, change my battery, all parts of Jaguar runs on electricity, main computer now runs faster, no delay on screen, and now Dsc not available once ignited doesn't appear anymore, remember that once car is reset by battery change, you need to apply brake and boot (step on brak and hold park brak lever up at the same time with pressing computer button on stearing whisk for like 10 sec until you see on screen AVE back again), and bypass radio lock by pressing on the three buttons, mem and the right combination with >>, and you're set