Self diagnostic test on cruise control switches on a 2004 Peterbilt C-15 475, it flashes once then pauses and flashes 6 times. I take that it means it's a code 16 but I can't find anything about a code 16 online anywhere. I've seen people post that the codes are in the owner's manual but of course there wasn't one in the truck when I got it . If anyone can help me with this, I would really appreciate it.