I have the CEL P0446 on my '97 Expedition. I read some great information on the Forum and turned to the EVAP canister in the back. I pulled off the electrical connector and confirmed I had 12 volts between the two terminals when the key was on run (engine off). I then pulled the canister and put 12 volts of battery to the solenoid and heard it click. I cleaned the filter and hose then put it back on the truck, but I couldn't hear the solenoid click when I plugged in the connector with the ignition on. Thinking I might not be able to hear the solenoid when it was on the truck, I took it off, went to the truck's battery and energized the solenoid. I could not only hear it, I could feel it click. I then confirmed I still had 12 volts at the connector. Thinking it might be a bad connector, I ran jumper wires from the connector to the solenoid. If I put a volt meter on the jumper wires, I got 12 volts, but no solenoid click when I touched the solenoid leads. When I took the canister back to the truck's battery and touched the leads, the solenoid energizes. I then checked the resistance across the solenoid and it read 54 ohms.

I am totally stumped. I have 12 volts (14 with the engine running) at the connector, but the solenoid won't energize. If I put battery voltage directly to the solenoid it energizes. What am I missing??

I really appreciate any advice you may offer.

Thanks,

Jim

 

Did you measure the voltage when you had it attached to the solenoid leads.
You might have too much resistance in the line. I would disconnect the positive cable at the battery then run jumper cables from the battery cable to the solenoid area so you can measure resistance from the solenoid connector to the jumper cables. Measure both the positive and ground wires.

 

Very interesting, I give it a try this evening and report back. Thanks for the tips.

Jim

 

You're missing the ground which is what the PCM provides when the solenoid is to be energized. You're supposed to have a "hot" lead there any time the ignition switch is in RUN.

 

I was wondering if that might be the case. I don't know if it's related, but when I was doing some testing last night I had the truck on run with the heads on for about 15 minutes and when I went to start the truck, the battery was dead. Being only 18 months old, I took it to the store where I bought it and they confirmed it was bad. I changed the battery and put it back together. We'll give it a try over the next few days. If I still get the code, I'll probably need to focus on vacuum unless anyone has any advice on trouble shooting.

Thanks again,

Jim

 

Either your gas cap is loose or the gasket for it isn't sealing.

 

The Canister Vent Solenoid is normally open. When the PCM decides it is time to do an EVAP Monitor test the PCM provides the ground for the pink wire which closes the CVS.

The p0446 is saying that the Fuel Tank Pressure Sensor reported the pressure to the PCM and the PCM determined that there was too much vacuum in the tank.

Too much vacuum in the tank could be caused by the Canister PURGE Valve (on the firewall) stuck open (or not sealing), or a kinked purge hose (has the tank been removed and reinstalled?)

Or when the PCM decides to purge the canister, if the canister is plugged or the CVS is stuck closed the FTPS will see the vacuum in the tank increase as the PCM tries to purge the canister.

Or the FTPS may be reporting erroneous pressures.

 

Thanks for the thoughts. The tank has not been removed, but I will check the purge valve on the firewall.

Jim

 

does anyone have a wiring pin connector for a 2003 aviator 4wd 4.6L thanks

 

Which connector?

 

ops ! smh I'm looking for the PCM pin connector wiring on this 2003 aviator 4.6L 4wd

 

The Aviator is kin to the Mountaineer and the Explorer not the Expedition or Navigator so our information in this forum might be a bit limited for you, but here are the pinout for the 3 connectors you needed.

 

Here is the Aviator forum: Explorer, Sport Trac, Mountaineer & Aviator - Ford Truck Enthusiasts Forums