Chevrolet TrailBlazer Key Replacement (2002-2009)

If you still have two working keys, you can attempt the 10-minute GM relearn procedure to add a third. If you only have one key or zero keys, no. The 2005 TrailBlazer uses a Pass-Key III+ immobilizer that requires a professional scan tool for single-key or all-keys-lost situations. We handle this on-site with our Tech2 and Autel IM608 for well under dealer prices. Call us at (805) 790-8162 and we will sort it out in your driveway.

Start with the original key and a simple ignition cycle. Disconnecting the battery resets the BCM (body control module), which means the transponder needs to relearn. Put your original key in the ignition, turn it to ON, wait 10 minutes for the security light to go off, then try starting. If that does not work, the issue is likely a worn ignition cylinder or a failing cluster, both common on the GMT360 platform. We diagnose and fix this mobile anywhere in Ventura County.

Yes, identical keys. The 2002 through 2009 EXT shares the exact same remote head key, transponder, and blade profile as the standard TrailBlazer. The only difference we see in the field is that EXT models have longer bodies, which puts more stress on the door cylinder actuators over time. The key itself is the same part number, same programming, same everything. We stock both and can handle either model on-site.

Here is the honest answer: the hardware is the same, but the SS trim can be a little pickier. V8 models with the 5.3L or 6.0L use the same Pass-Key III+ system as the inline-six, so the OBD-II programming procedure works across all 2002 through 2009 TrailBlazers. The SS sometimes has a tighter immobilizer sync that rejects cheap clone chips. We extract the PIN reliably with our tools and use quality blanks, so this is not an issue when we do the job. Avoid the bargain bin keys on Amazon for the SS.