Spare Key Programming — Unlimited Key Mode

Special Tool(s)

Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool

Enabling Unlimited Key Mode

NOTE: Unlimited key mode is intended for use by those customers who need more than 8 keys for their vehicle.

NOTE: If unlimited key mode is enabled (or disabled), a maximum of 4 Integrated Keyhead Transmitter (IKT) keys can be programmed to the vehicle for Remote Keyless Entry (RKE) functionality. If more keys are required, they should be standard Passive Anti-Theft System (PATS) keys. If more than 4 IKT keys are programmed to the vehicle, the Smart Junction Box (SJB) sets DTC B1138 (Memory Full), the IPC sets DTC B109E:42 (Remote Keyless Entry: General Memory Failure) and only 4 IKT keys have RKE functionality, however, all of them start the vehicle, if programmed correctly.

NOTE: Before programming, the new key(s) must have the correct mechanical cut for the ignition lock cylinder.

NOTE: The unlimited key mode is set up by creating a special, unique unlimited transponder security key code and programming this key code into all of the vehicle keys so they contain the same key code.

NOTE: When in the unlimited key mode, the N_KEYCODE PID in the IPC always reads 2, no matter how many keys are programmed to the vehicle (after the first 2 keys have been programmed).

1. The customer must choose an 8-digit number (except for 00000000 or 00000001) to be programmed to all of their vehicles. All customer vehicles need to use the same number. Valid digits are 0-9 and the letters A-F.

2. NOTE: If the IPC PID UNL_KEY_ID is not available, unlimited key mode is turned on and must be turned off before viewing the stored code. At this time, unlimited keys can be programmed to the vehicle. To view/disable/change the stored code, follow the procedure for disabling the unlimited key mode below.

   Monitor the IPC PID UNL_KEY_ID and compare its value against the code chosen in Step 1. It should not be the same key code.

3. 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 section.

4. Once in security access, select: "program unlimited key code" and follow the IDS on-screen instructions. Enter the 8-digit code chosen by the customer in Step 1 of this procedure and follow the IDS on-screen instructions.

5. Select: "unlimited key mode ON" and follow the IDS on-screen instructions.

6. Select: "Ignition Key Code Erase" and follow the IDS on-screen instructions.

7. Disconnect the scan tool and turn the ignition switch to OFF (the key does not need to be removed at this time).

8. Turn the first PATS key to the ON position for 3 seconds (6 seconds if it is an IKT key).

9. Turn the first PATS key to the OFF position and remove the key from the ignition lock cylinder.

10. 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).

11. Start the vehicle with both PATS keys. The vehicle now starts with both PATS keys.

12. If it is desired to program additional key(s), refer to Key Programming Using Two Programmed Keys in this section for each additional key that needs to be programmed.

Disabling Unlimited Key Mode

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

1. From the scan tool, enter TOOLBOX. Select BODY-SECURITY-PATS Functions and follow the IDS on-screen instructions to ENTER SECURITY ACCESS. For additional information, refer to Anti-Theft Security Access in this section.

2. Select: "unlimited key mode OFF" and follow the IDS on-screen instructions.

3. Select: "Ignition Key Code Erase" and follow the IDS on-screen instructions.

4. Disconnect the scan tool and turn the ignition switch to OFF (the key does not need to be removed at this time).

5. Turn the first PATS key to the ON position for 3 seconds (6 seconds if it is an IKT key).

6. Turn the first PATS key to the OFF position and remove the key from the ignition lock cylinder.

7. 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).

8. Start the vehicle with both PATS keys. The vehicle now starts with both PATS keys.

9. NOTE: With the unlimited key mode turned off, a maximum of 8 keys can be programmed into the IPC using the Key Programming Using Two Programmed Keys procedure in this section. The IPC PID SPAREKEY must be enabled.

   If it is desired to program additional key(s), refer to Key Programming Using Two Programmed Keys in this section for each additional key that needs to be programmed. The PID SPAREKEY must be enabled.