I am getting a P0446 code and it states that it is the vent contol circuit. Does anyone have a diagram stating where all the parts and names for the EVAP system? The truck has had the TSB update as it has a 08 canister in it and the hose is relocated to the bed of the truck. Took everything out, blew it out with air..and cleaned the electrical hook up that is by the canister also with some good electrical cleaner. So I am trying to figure out what next..and the diagram will tell me what is what. Thanks

 

Any code that says "circuit" means the PCM doesn't see the correct voltage or drain in the circuit to that solenoid/sensor. Sounds like an electrical problem, as in wiring or the solenoid itself.

On the other hand, that code lists as "P0446 Evaporative Emission Control System Vent Control malfunction." No "circuit" just malfunction.

A good blurb from the Ford book is available in this thread: https://www.ford-trucks.com/forums/9...6-97-5-4l.html

Since you've already checked the hoses and such, I suspect it's the purge solenoid is stuck.

 

Krewat,

I did read that one, when I was looking for the diagram which tells what is what..Here is an update on my situation. I also had a 1633 (I belive) code which was low voltage code also. I read somewhere where a guy had a fuse blown and that was his issue. So I thought I would check all my fuses. I took all of them out and checked them. They all checked out good. Started the truck up to go into town...no service light..drove in town and all the way home..and back into town..no service light..not isn't that just pure amazing..not sure how that works..but now it is not throwing any codes??????????? But you were stating the purge selonoid, is that the one located by the charcoal canister with the electrical connection? I know there is one under the hood also..but like I stated, I am not sure what is what...another issue it is having is when I fill up with gas..it does not shut off the pump right away, and fuel spews out

 

buzter, I have the opposite problem with the fuel fill. I have problems with getting the fuel in the hole. I'm sure some nozzles are a bit more sensitive than others, but sometimes I have to nurse the thing for 5 minutes just to put 30 gallons in it. It drives me nuts. Other times it drinks like a college student, chug a lug!
Have you tried other stations/pumps to see if they don't shut off either?
I need to perform the TSB on mine for the evap cannister, maybe that will fix my slow fill? I also noticed the 5/16" vent tube on the side of the fill tube. THAT ain't helping much.