For sure the pin is yours you create it. You only need the VIN number from the care.
I dont remeber really well but these are the steps
1.Download the app on my Iphone
2. Create an account using the phone app
3. This will the redirect you to the Jaguar Site
4. Here you will put in your details plus VIN number
5. When you click Next it will ask you to create a Password to access the account but will also ask you to create a 4 digit pin .
6. Once you input the details you can confirm.
7. Jaguar will send you a email confirmation
8. You need to click the link in the email Jaguar has sent to your personal email.
9. No you should be able to use the app on the phone.
10. If your car data is still not correct on the app and you have some of the option greyed out then you will need to access the Jaguar site again and complete the setup which will be registration of the car.
Step 10 was the part I was missing. As for the pin its your own pin the only thing you require fron the car is the VIN
There is a stage once you are creating the account on the app it will ask you to go to your car and press the button so that it links in.