My brother was the parts manager at a local GM dealer, so any time I brought my truck in for any work, he would show me how they did everything. I learned a lot, especially about how security is handled differently between each of GM’s brands. This was a few years ago, so full disclosure as I might be missing some of the details.
Like Cadillac, the OEM Hummer key uses a harder metal to give the key teeth better longevity. Other GM brands may now use the harder metals, but when our rigs were new there was a notable difference. If anyone plans to purchase an OEM key, make sure the dealer has an updated key cutting machine onsite. It will be approved by GM for cutting Cadillac keys, or you could take it to a Cadillac dealer to be cut. If this happens, ask the dealer to ask the Caddy dealer for a courtesy cut. Before my brother left that dealership, he told me that all GM dealers were slowly updating to the new machines. I’ll try to remember to look for my receipts tonight, but I am pretty sure I paid $60 for the OEM key with my brother’s employee discount, so it is worth trying to talk them down, especially if you are paying to program new fobs at same time (or any other work they can use to support the discount). Most of you probably already program all of your fobs at once because it requires a Tech 2 and shop labor. I seem to remember the first fob programmed becomes the master fob, and it is the only fob that can be used to reprogram any other ”smart” device that is part of the security system (ECM, BCM, ignition, etc. I am not sure about the TCM). Our keys are not chipped, so to match the security of a chipped key, they put the chip in the fob instead. Does anyone know why GM defines a primary fob? I‘d love to know the story behind it.
If anyone is planning a key and fob refresh, I recommend making 5 keys:
2 masters stored in two different safe & secure locations (safe deposit box in a bank, nearby close family’s house in a secured safe, etc.).
1 primary on a fob for every day use
1 secondary on a fob for every day backup (If I am running late and don’t have time to look for my keys, I can grab the backup. But then I need to make sure to locate my primary set and replace the backup set when I return home)
1 hidden backup somewhere on the vehicle (with a fob so the security system can be disabled in case the primary set is lost while traveling).
Keep inventory on them on a regular basis
One or both masters can be hardware store keys as long as they are created from an OEM key. I replace my primary key from the hardware store every few years to avoid being stranded if/when the teeth were to ever wear down enough to not operate the ignition. This replacement habit of mine is probably a little extreme, but I am a big fan of being pro-active with anything related to security.
Hope this helps.
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