So, my truck is a 2006 CTD w/ an auto. Monday night I started it and the alarm light came on and the horn blew and the light stayed on. The airbag light was also lit. I shut the truck off and used my remote to lock and unlock the truck to disable the security system. The alarm light went out but the airbag light stayed on. It later went out and back on and back out a few times on the way home. I did have it parked along a state forest road in a somewhat remote location, so its possible that someone tried to open the door or bumped it.

Tuesday night I drove it and the airbag light was on and off again and the high beams came on and off by themselves. I ran the codes and U1403 came up which is an "Implausable fuel level signal". I unhooked the batteries for a few minutes and started it back up and ran the codes again; this time no codes. I did fill it up with fuel Tuesday morning.

Wednesday (tonight) I started it and it shut off immediately and the horn blew (engine immobilizer). Started it again, it runs fine. Airbag light is still coming on and off and running the codes yields U1403.

Sorry for the lengthy post but, has anyone experienced anything similar to this or have any ideas to the cause?? I dont trust my local dealer to figuring this one out on their own.