I had posted previously on this prob, I still haven't got anywhere. Any ideas? I have a 6 stack unit from a VY, I want to put it in my VZ, but when I do the factory PIN doesnt work. It powers up okay, but gives you three goes with the PIN (which has been double checked) and then locks me out for an hour. Holden have been no help what so ever!!! THe serial numbers and VIN for the original car are as follows VIN, it's 6G1YK42F84L189843 and the serail number of the unit is BP 2256 41241707, the other numbers on the unit are LP 8 635 123 247 2 as well as 92 118 704. this last one is on a sticker on the back of the unit.