Originally Posted by Asur
If you just push the start button without hitting the brake this should put the truck in ACC just as if it were a key. Once you do the below mentioned setup, the red seat belt light will still be lit, and the EVIC will still show the alert but the chime is disabled. Also doing the trick again will enable the chime again.
Do the following to disable it:
Start with the doors closed, ignition off. fasten your seat belt. push button to ACC mode with foot off the break, watch the seat belt light. when it goes off, unbuckle re-buckle the seat belt 3 times within 10 seconds, and immediately push button to off it will chime once to tell you if this was done successfully.
This worked great but you have to press the start button twice with the foot off the break to get the seat belt light to illuminate on the dash.
Thanks a bunch for the tip!!!