How many unique key and chip combinations are there?

[RiffRaffMama]

I just had a really strange experience. My husband and I own about ten Commodores, mostly VTs and VXs, but there's a couple of stand-alones, including the single VZ we own. I had to get something out of the locked VZ (Exec) and the key wasn't where it was meant to be. So after searching for ages I was getting desperate and in spite of my common sense telling me I was being stupid, I grabbed a handful of different Commodore keys and went out to the VZ. I tried my VX Berlina key in the VZs driver door and not surprisingly, nothing happened. I tried another Commodore key and nothing happened (not sure which car it belongs to - some are labelled, other times you just grab a handful of keys and try your luck until you hit on the right one). Then I tried my VT Berlina's key and the bloody VZ opened. All locks popped up, no alarm went off and I was able to get into the car.
Before anyone asks, yes, I am absolutely certain this is the VT key and not a spare of the VZ.
I could not try the VT remote, because its battery is flat, so I don't know if this works the same also. I have not yet tried the VZ key in the VT.
The worst part though, was when I tried starting the car. The battery in the car was almost flat, but I was still able to turn the key in the ignition and it clicked rapidly but didn't turn over, like you can expect a car with a mostly flat battery to do. I am almost convinced that it will turn over when the battery is charged***. Later on I managed to find the actual VZ key and it made the same clicky-no-start noises as the VT key, so the bcm was treating both the legit and the imposter keys the same.

How has this happened? The likelihood of it happening are at least 1000:1 and that's because there is legislation in place to mandate that across the country. How many Commodore key/chip combinations are there?

Edit: My husband has just charged the battery in the VZ and informed me that the VT key starts the VZ also.

When I found the VZ key I took this side-by-side photo for a comparison of their appearance:

And here is a video of the cuts being compared:

 

[Immortality]

I had a similar thing with my old VH many moons ago. I'd locked the keys in the car at tech, there was another Commodore in the parking lot so I waited for that guy to come out and asked to borrow his keys. To both our surprise his keys unlocked my passenger side door...


As much as I appreciate your enquiry, I'm not sure that sort of info should be shared if someone actually knew the number. What I do know is the system works on a rolling code so invariably the same combination is going to come up.

 

[krusing]

I just had a really strange experience. My husband and I own about ten Commodores, mostly VTs and VXs, but there's a couple of stand-alones, including the single VZ we own. I had to get something out of the locked VZ (Exec) and the key wasn't where it was meant to be. So after searching for ages I was getting desperate and in spite of my common sense telling me I was being stupid, I grabbed a handful of different Commodore keys and went out to the VZ. I tried my VX Berlina key in the VZs driver door and not surprisingly, nothing happened. I tried another Commodore key and nothing happened (not sure which car it belongs to - some are labelled, other times you just grab a handful of keys and try your luck until you hit on the right one). Then I tried my VT Berlina's key and the bloody VZ opened. All locks popped up, no alarm went off and I was able to get into the car.
Before anyone asks, yes, I am absolutely certain this is the VT key and not a spare of the VZ.
I could not try the VT remote, because its battery is flat, so I don't know if this works the same also. I have not yet tried the VZ key in the VT.
The worst part though, was when I tried starting the car. The battery in the car was almost flat, but I was still able to turn the key in the ignition and it clicked rapidly but didn't turn over, like you can expect a car with a mostly flat battery to do. I am almost convinced that it will turn over when the battery is charged. Later on I managed to find the actual VZ key and it made the same clicky-no-start noises as the VT key, so the bcm was treating both the legit and the imposter keys the same.

How has this happened? The likelihood of it happening are at least 1000:1 and that's because there is legislation in place to mandate that across the country. How many Commodore key/chip combinations are there?
When I found the VZ key I took this side-by-side photo for a comparison of their appearance:

View attachment 221976

VERY similar cut also !

 

[Dayvo]

Similar thing happened at work some years ago , one guy had a vr wagon and the other had a vr statesman and their remotes could open each others cars.

 

[Lex]

Similar thing happened at work some years ago , one guy had a vr wagon and the other had a vr statesman and their remotes could open each others cars.

Same here. About 20 years ago l had Toyota hi ace van. I had locked my keys in the van. Mate turned up in his late model Camry, & suggested he try his key on the van. Yeah sure. Buckleys chance!
Surprise surprise the newer Camry key opened the older Hi ace.

 

[RiffRaffMama]

Same here. About 20 years ago l had Toyota hi ace van. I had locked my keys in the van. Mate turned up in his late model Camry, & suggested he try his key on the van. Yeah sure. Buckleys chance!
Surprise surprise the newer Camry key opened the older Hi ace.

Old Toyotas are notorious for that. I've owned two old Celicas and you can use any old Celica key to open and run any other old Celica.
And Datsun utes, too. My husband got my Celica stuck on an embankment one night so we needed to borrow his father's old Datsun ute that we didn't have the keys for. Turned out the Celica key drove it too.

 

[RiffRaffMama]

VERY similar cut also !

I had to see just how similar so I made one key semi transparent in Photoshop and dragged it over the other key. Yeah, they're not similar, they are the same. I screenshot me doing it:

 

[s_ikari2015]

I'm going to say the VATS has been disabled on the VZ, thus why the VT key starts the car. Try swapping the fob with any other one and see if they also starts the VZ using the same metal key part (they are clearly the same bitting). If the third fob doesn't start, then yeah, lucky you have two fobs that are "synced"