As a seemingly perpetual AU beginner, I am probably only 1 step ahead of you, having done a job in this area once, but in theory I should be able to give you the pointers you need when you are ready.
I won't go into detail on anything now, as I am just going from memory, and I think it's all been included already in this thread. But if not, and you get stuck, then ask again then.
Forscan is what you need but those functions are not where you solve this problem.
You need to install the extra licence/functions (this doesn't cost much and may be free for a short time) to get the PATS reset.
What has happened to you is likely you have lost the hand shake between Keypad and
BEM/
BCM (maybe the
PCM/
ECU/ECM is involved but that is not really relevant yet).
Your problem may or may not mean you have a faulty component.
But you will know that after you complete the process, if the problem has been resolved or not.
If you still have a problem then it will most likely be a faulty
BEM.
And for series 2 and 3 6cyl I believe they all use the same pink one?
You also use PATS to make the new
BEM talk to the existing
PCM as well as the keys.