Identifying this chip in your vehicle
The PK3 (Passlock III) chip is manufactured by GM (in-house) and is used across 45 model-year combinations in our directory, spanning 2 manufacturers. The chip operates at 125 kHz LF with 40-bit fixed encryption.
You won't find the chip name printed anywhere on a typical fob — the chip is a millimeter-scale die embedded under the plastic. The fastest way to confirm whether your vehicle uses the PK3 (Passlock III) is to look up your year/make/model on KeyFob Guide; we've cross-referenced every entry against manufacturer data sheets and the OBD2 community immobilizer database.
Aftermarket fob shopping
Reputable aftermarket sellers list the transponder chip family in the product description. When shopping for a fob compatible with the PK3 (Passlock III), look for one of the following phrases on the listing: "PK3 (Passlock III)", "40-bit fixed chip", or the manufacturer's part designation. Generic listings that say only "fits 2010-2020 [model]" without naming the chip should be treated with extreme skepticism — the wrong chip will pair the keyless entry side but fail the immobilizer handshake, leaving you with a fob that locks the doors but won't crank the engine.
Top programmers for this chip
Across the 45 vehicles using the PK3 (Passlock III), the most broadly compatible aftermarket programmers in our index are:
- Autel MaxiIM IM508 — 45 compatible vehicle pages. Autel's entry-level immobilizer programmer. Strong U.S. domestic coverage (GM, Ford, Mopar) without per-vehicle license fees. PEPS pairing on most pre-2018 vehicles.
- Autel MaxiIM IM608 Pro — 45 compatible vehicle pages. Autel's flagship programmer. Adds full EEPROM read/write capability via the included XP400 Pro adapter, plus J2534 reflashing.
- Xhorse VVDI Key Tool Plus — 45 compatible vehicle pages. Tablet-form pad and programmer combo with strong European and Asian coverage. VVDI's annual update cadence is faster than competitors.
- AutoProPAD G2 — 45 compatible vehicle pages. Locksmith-favorite tablet programmer with strong U.S. truck and SUV coverage. Excellent at all-keys-lost on Ford, GM, and Mopar PEPS systems.