GMC Key Replacement
GMC key replacement in the Hudson Valley — GMC shares GM’s immobilizer systems, and what that means for Sierra, Yukon and Terrain owners.
Call or text with these and we’ll take it from there
- Year, make and modelIt decides the key and the equipment.
- Any working key?Adding a spare and starting from none are different jobs.
- Where the vehicle isDriveway, lot, roadside — and whether it can be driven.
We come to you
Driveway, lot or roadside
Call or text
Same number, either way
Ownership checked
ID and paperwork, every job
Keys, fobs & remotes
Every kind, one call
GMC shares its immobilizer and key systems with the rest of General Motors. A Sierra and a Silverado of the same year use the same security architecture, which means the answer for your GMC is the answer for its Chevrolet equivalent.
That’s genuinely useful rather than a shortcut: it means the documentation covering GM as a whole applies to your vehicle.
The three eras
Roughly 1995 to 2004 — Passlock. Security lives in the ignition lock rather than the key. A magnet in the cylinder and a sensor beside it; the key itself is an ordinary cut blade with no chip. Replacement keys for these are simple mechanical work.
Passlock also allows three failed reads before entering Long Tamper Mode, which disables the engine for about ten minutes. If your older GMC has stopped responding after several attempts, that may be what’s happening rather than a fault.
There’s an onboard relearn requiring no tool: ignition to ON or RUN for about ten minutes until the security light stops flashing, repeated three times on Passlock II vehicles.
Roughly mid-2000s onward — transponder keys. GM moved to PassKey III with a chip in the key head. We’re not going to quote model-year cutoffs, because GM staged the change by model and the public record doesn’t map it cleanly for GMC specifically.
2020 model year onward — credentialed security data. GM gates key programming behind its Secure Data Release Model. Every tool, dealer or independent, has to obtain security data through a credentialed request before programming a key — for adding a spare and for all-keys-lost alike. There’s a mandatory waiting period built in, around two hours for vehicles serviced after February 2023.
A shop without that registration can’t do the work at all.
A documented fault worth ruling out
GM bulletin 21-NA-244 describes a body control module fault producing a “No Fob Detected” message and a no-crank, no-start condition, with a distinctive symptom: the fob still works when you press the buttons but the vehicle won’t detect it passively.
The bulletin names the 2021–2022 Yukon among affected vehicles.
If that matches, a replacement fob won’t help — it’s module work at a certified facility.
Need a key sorted? Call or text — same number.
Why this page is shorter
Because GMC’s key systems aren’t separate from GM’s, and pretending otherwise would mean padding.
Where a source names GMC vehicles specifically — Sierra, Yukon, Yukon XL, Denali, Hummer EV — we’ve said so. Everything else is corporate-wide GM architecture that verifiably includes GMC nameplates.
For the fuller treatment of each era, our Chevrolet page covers the same systems in more detail. It applies to your GMC.
What we do on site. We cut and program GMC keys and fobs on site, including all-keys-lost, on models up to about 2019. Many 2020-and-later Sierras, Yukons and Acadias use GM’s newer electrical system, which needs an online manufacturer session with a built-in wait; some of those go to the dealer. Tell us the year and we’ll say which.
What to have ready
- Model year and model
- What the key looks like — plain blade, thick plastic head, or a fob
- Every key you own
- Proof of ownership — registration or title, and matching photo ID
What it costs
Depends entirely on which era your GMC falls in. What determines car key replacement cost covers what moves the number.
Fob just stopped working? It may only be the battery.
Key fob battery guideFrequently asked questions
Are GMC keys the same as Chevrolet keys?
The systems are shared. GMC and Chevrolet vehicles of the same generation use the same GM immobilizer architecture, so the process is the same.
Does my older GMC key have a chip?
If it’s from roughly 1995 to 2004, probably not — GM’s Passlock system keeps the security in the ignition lock rather than the key.
My GMC won’t start and the security light is on.
After several failed attempts, Passlock-era vehicles enter a roughly ten-minute lockout by design. Wait before assuming a fault.
Why can’t every locksmith program a key for my 2021 Sierra?
From the 2020 model year, GM requires credentialed security data before any tool can program a key. Shops without that registration can’t do it.
My Yukon’s fob works on the buttons but won’t start the truck.
A GM bulletin describes that exact pattern as a body control module fault on certain 2021–2022 vehicles. A new fob won’t fix it.
Locked out or lost your key? Call The Fobfather