Hummer Key Specialist
Same-Day Service

Yes, for all original Hummer models. H1 keys are basic cuts with no transponder on most models, requiring only a blade duplication. H2 and H3 models use GM's PK3 transponder system and program through OBD-II using Autel IM608 and GM Tech2-compatible tools on-site. All-keys-lost situations on the H2 from 2008 onward and the H3 from 2006 onward are fully serviceable without towing by a qualified locksmith. The GMC Hummer EV uses the Ultium platform proximity fob system, and we handle those on-site with updated GM programming tools as well.

Passlock is GM's resistance-based immobilizer system used in the H3 from 2006 through 2010. The ignition cylinder contains a sensor that reads a resistance value from the key, and if that reading does not match what the BCM expects, it disables the fuel pump and prevents starting. A flashing security light usually means the Passlock sensor got an incorrect or no reading, which can happen after a battery disconnect, in cold weather, or as the sensor wears over time. The standard recovery is to leave the ignition in the On position for 10 minutes until the security light goes out, then try to start normally. If that does not work, the cycle can be repeated up to three times. If the problem recurs frequently, the ignition cylinder sensor is likely wearing out and needs replacement.

Turn the key to the On position without cranking the engine. Watch the security light on the dashboard. Leave it in this position for 10 full minutes until the security light turns off or stops flashing. Once the light goes out, turn the key back to Off, wait a few seconds, and then try to start normally. If it does not start, repeat the sequence up to two more times. Do not try to crank the engine during the 10-minute wait, as this resets the timer. This resets the Passlock module and allows the BCM to re-sync with the ignition cylinder sensor.

Most civilian H1 models do not. The H1 was built on military vehicle architecture and retained basic mechanical keys for most of its production run from 1992 through 2006. Some later civilian Alpha models from around 1996 onward added remote keyless entry fobs for door cylinders, but these used fixed codes rather than rolling-code transponders and did not have an immobilizer system tied to key recognition. Cutting an H1 key requires knowing the correct blade profile, but no programming is involved on virtually all H1 models.

Simultaneous dual-fob failure on the H2 is almost always a vehicle-side issue rather than both fobs dying at once. The most common cause is a desync event triggered by a battery disconnect, an electrical reset, or a failing door ajar switch that puts the vehicle into security mode with the dome lights on and the radio drawing power. New CR2032 batteries in the fobs will not fix this because the fobs are still programmed correctly, they just lost sync with the BCM. We can resync both fobs on-site via OBD-II in a few minutes. Check whether the door ajar indicator is showing when all doors are closed, as that usually points to the switch as the root cause.

H1 key replacement is inexpensive since it is a basic blade cut with no programming. H2 and H3 transponder key and fob replacement is comparable to other GM truck platforms, with dealer programming labor running $80 to $150 on top of part costs. The GMC Hummer EV smart key fob costs $300 to $400 at the dealer before any towing or labor is added. We handle H2, H3, and EV key service on-site at competitive pricing. See the table above for exact figures by key type.

On 2008 and 2009 H2 models, a timed ignition cycle sequence can program new transponder keys without professional tools. The process involves three separate 10-minute ignition cycles with the new cut key, after which the immobilizer learns the new key. This only works for transponder key programming, not for the remote fob functions, which require OBD-II BCM access. On earlier 2003 through 2007 H2 models, on-board programming is not available and a working master key is typically needed. We can complete any of these jobs in a fraction of the time using our programmers.