Passkey III – transponder ignition key
The Passkey III anti-theft system uses a transponder inside the head of the ignition key. The
exciter inside the ignition lock cylinder energizes this transponder when the ignition switch is
turned on. The transponder transmits a unique signature to the theft deterrent control module.
If the key signature transmitted is acceptable to the theft deterrent control module, the theft
deterrent control module will transmit fuel enable password to the PCM. If the fuel enable
password is correct, the PCM will start the vehicle.
To perform a relearn on a Passkey III system, make sure there is a fully charged battery in the
vehicle. The battery will be used for 30 minutes without the alternator available for charging.
Connect a battery charger to the battery to ensure power is available while programming.
When performing this relearn, all previously learned keys will be erased. Additional keys may
be relearned immediately after the first key has been learned by inserting the additional key
and turning the ignition switch to on within 10 seconds of removing the previously learned key.
1. Insert a master key (black head) into the ignition switch.
2. Turn key to the “ON” position without starting the engine. Security light should turn on and
3. Wait for 10 minutes or until the security light turns off.
4. Turn key to the “OFF” position for 5 seconds.
5. Turn key to the “ON” position without starting the engine. Security light should turn on and
6. Wait for 10 minutes or until the security light turns off.
7. Turn key to the “OFF” position for 5 seconds.
8. Turn key to the “ON” position without starting the engine. Security light should turn on and
9. Wait for 10 minutes or until the security light turns off.
10. Turn key to the “OFF” position. The key transponder information will be learned on the next
11. Start the vehicle. If the vehicle starts and runs normally, the relearn is complete. If additional
keys need to be relearned:
12. Turn the key to the “OFF” position.
13. Insert the next key to be learned. Turn the key to the “ON” position within 10 seconds of
removing the previously used key.
14. Wait for security light to turn off. It should happen fairly quickly. You may not notice the
lamp, as the transponder value will be learned immediately
15. Repeat steps 12 through 14 for any additional keys.
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Address 9131 Highway 71 NE, Spicer, MN, 56288
1 thought on “GM Passlock Relearn”
What a pleasure it was to speak with Joyce , true professional with kindness , courtesy, great listening skills and offered some valuable information i didn’t know to ask….Made my purchase immediately after speaking with Joyce….Now , here’s hoping shipping comes through…THANK YOU JOYCE…