Disabling Unlimited Key Mode

NOTE: By disabling the unlimited key mode, the previous access code no longer operates the vehicle.

From the scan tool, enter TOOLBOX. Select BODY - SECURITY - PATS Functions and follow the Integrated Diagnostic System (IDS) on-screen instructions to ENTER SECURITY ACCESS. For additional information, refer to ANTI-THEFT SECURITY ACCESS in this article.
Select: "unlimited key mode OFF" and follow the IDS on-screen instructions.
Select: "Ignition Key Code Erase" and follow the IDS on-screen instructions.
Disconnect the scan tool and turn the ignition key to the OFF position (the key does not need to be removed from the ignition lock cylinder at this time).
Turn the first Passive Anti-Theft System (PATS) key to the ON position for 3 seconds (6 seconds if it is an Integrated Keyhead Transmitter (IKT) key).
Turn the first PATS key to the OFF position and remove the key from the ignition lock cylinder.
Insert the second PATS key into the ignition lock cylinder and turn the key to the ON position for 3 seconds (6 seconds if it is an IKT key).
Start the vehicle with both PATS keys. The vehicle should now start with both PATS keys.
NOTE: With the unlimited key mode turned off, a maximum of 8 keys can be programmed into the Instrument Cluster (IC) using the Key Programming Using Two Programmed Keys procedure in this article. The IC PID SPAREKEY must be enabled.
If it is desired to program additional key(s), refer to KEY PROGRAMMING USING TWO PROGRAMMED KEYS in this article for each additional key (up to 8 keys, total) that needs to be programmed. The IC PID SPAREKEY must be enabled.