This was for the 4th Gen:
If desired, the "Sound Horn On Lock" feature can be turned on and off by performing the following procedure:
1. Press the LOCK button for 5 to 10 seconds.
2. While the LOCK button is pressed (after 5 seconds), press the PANIC button. Release both buttons.
The "Sound Horn On Lock" feature can be reactivated by repeating this procedure or by performing the procedure in the Electronic Vehicle Information Center (EVIC), Customer Programmable Features section on vehicles so equipped.
If desired, the "Sound Horn On Lock" feature can be turned on and off by performing the following procedure:
1. Press the LOCK button for 5 to 10 seconds.
2. While the LOCK button is pressed (after 5 seconds), press the PANIC button. Release both buttons.
The "Sound Horn On Lock" feature can be reactivated by repeating this procedure or by performing the procedure in the Electronic Vehicle Information Center (EVIC), Customer Programmable Features section on vehicles so equipped.