Hummer Keys, Classic and EV
H1 H2 H3 Mobile

Yes for every Hummer ever sold. Breakdown by model. H1: basic blade cut, no transponder on most civilian builds, just key duplication. H2 and H3: GM's PK3 transponder system, programmed through OBD-II using Autel IM608 and GM Tech2-compatible tools at the truck. All-keys-lost on the H2 (2008 onward) and H3 (2006 onward) is fully serviceable mobile by a qualified locksmith with the right tooling. GMC Hummer EV: Ultium platform proximity fob system, handled at your truck with updated GM programming tools. None of these require a dealer trip.

Passlock is GM's resistance-based immobilizer system, used in the H3 from 2006 through 2010. There's a sensor in the ignition cylinder that reads a resistance value from the key, and if that reading doesn't match what the BCM expects, the fuel pump shuts off and the engine refuses to start. A flashing security light means the Passlock sensor either got no reading or got the wrong one. Common triggers: a recent battery disconnect, cold weather, or a sensor that's worn from years of use. The standard recovery procedure is leaving the ignition in the On position for 10 minutes until the security light extinguishes, then trying to start normally. If the first attempt doesn't work, you can repeat the cycle up to three times. Frequent recurrence usually points to the ignition cylinder sensor itself wearing out and needing replacement.

Step by step. Turn the key to the On position without cranking the engine, just power on. Watch the security light on the dashboard. Leave the key in that position for a full 10 minutes until the security light extinguishes or stops flashing entirely. Once it goes out, turn the key back to Off, wait a few seconds, then try a normal start. If it doesn't fire, repeat the same sequence up to two additional times. Critical note: do not attempt to crank the engine during the 10-minute wait. Any cranking attempt resets the timer back to zero. The procedure works by resetting the Passlock module and allowing the BCM to re-sync with the ignition cylinder sensor's resistance reading.

On almost every civilian H1, the answer is no. The H1 was built on military HMMWV architecture and AM General kept the civilian version mechanically simple, with plain metal keys throughout the production run from 1992 through 2006. Later Alpha civilian models from around 1996 onward added remote keyless entry fobs for the door cylinders, but those used fixed codes rather than rolling-code transponders, and there was no immobilizer system tied to key recognition on the ignition side. Cutting an H1 key requires the correct blade profile but skips the programming step entirely on virtually all civilian H1 models.

Dual-fob failure on an H2 at the same instant is almost never two coincidentally dead fobs. It's a vehicle-side BCM desync, and three things commonly trigger it: a battery disconnect, an electrical reset of some kind, or a failing door ajar switch that quietly puts the truck into security mode with the dome lights running and the radio drawing power overnight. Fresh CR2032s in both fobs won't restore function because the fobs themselves are still programmed correctly, they just lost sync with the BCM. We run an OBD-II resync at the truck and both fobs come back in a few minutes. Diagnostic clue: if the door ajar indicator is on with all doors closed, that switch is almost certainly the root cause.

Pricing splits cleanly by model. H1 replacement is the cheapest, since it's a basic blade cut with no programming step. H2 and H3 transponder key and fob replacement runs comparable to other GM truck platforms, with dealer programming labor adding $80 to $150 on top of part costs. The GMC Hummer EV smart key fob runs $300 to $400 at the dealer alone, before any towing or labor charges get added. Our mobile pricing handles H2, H3, and EV service at the truck at competitive rates across San Diego County. The table above shows exact figures by key type.

On 2008 and 2009 H2s, yes, partially. There's a timed ignition cycle sequence that programs new transponder keys without professional tools: three separate 10-minute ignition cycles run with the new cut key, after which the immobilizer learns the new key. The catch is what that sequence doesn't cover. It handles transponder key programming only, not the remote fob functions, which require OBD-II BCM access. On earlier 2003 through 2007 H2 models, on-board programming isn't available at all and a working master key is typically required. Either way, our programmers complete any of these jobs in a fraction of the time the DIY sequence takes.