I want to thank all those who have helped me either in my posts or without even knowing it just by participating. With your help, I have replaced my engine, then replaced the heads with new ones after the head gasket blew, and taken the trouble count down from 13 to 1. All of the above seemed easy compared to this.
I have a code P0443. No other codes. My research confuses me. I know where and what the purge valve solenoid is. I know where and what the purge valve is. I tested the purge valve by giving it 12 volts and seeing if it clicks. It didn’t. Cool, I though. But no, I’ve gotten 3 from the junk yard that don’t click and 1 brand new, the one that’s in it now, no click. Maybe I should only expect a click from the solenoid. I have replaced the solenoid and it clicks. I’ve followed the wires and found some corrosion and such. With the wiring all cleaned up, the blue/orange wire from solenoid to fuse 13 reads 1.5 ohms as does the purple/white wire from solenoid to PCM.
The only thing that sticks out to me is that if I unplug the wire connector to the flex fuel sensor, the P0443 goes away. Plug it back in and the P0443 comes back. I don’t know what that tells me but it seems important.

 

What year Ranger?
3.0l if flexfuel

When you unplug the 3 wire fuel sensor do you get the new code to check flex fuel sensor?

EVAP system uses engine Vacuum to pull gasoline vapor from the gas tank when driving and burns it in the engine
P0443 references the 2 wire purge valve that the computer uses to apply vacuum from the intake to the gas tank
Purge valve solenoid is an air valve, it gets 12v with key on on 1 wire
The other wire goes to computer, its the ground wire, computer Pulses the Ground wire(PWM) to control how far the solenoids valve opens

A solenoid has an internal Coil of wire around a metal core, when current flows thru the coil of wire the metal core becomes an electro-magnet, so same as a relay in that respect, but a Solenoid causes Movement, a relay connects electrical devices
In this case the solenoid moves an air valve to allow air to flow thru it, a little or a lot of air depending on the voltage/current that applied to the coil of wire

P0443 is a "circuit code" so either the computer is not seeing 12v with key on, or can not control air flow using the ground wire

The Flex fuel sensor has no common wiring with the Purge Valve
Only the computer is the common link
I know 2000 Rangers had a multi wire connector under the drivers seat, its a thru the floor connection, that could get water intrusion and lots of corrosion, C309,it caused odd codes and even engine running issues

 

Sorry, forgot the details. 2000 3.0 flex fuel 4x2 with auto transmission.
Yes, when I disconnect the flex fuel detector connector, I get the P0176 code for the flex fuel detector. But I now know that I’m still getting the P0443 off and on under those conditions.

Ron, you said that the flex fuel sensor shares no common wiring with the purge valve. This is where I get confused. I believe that it shares common wiring with the purge solenoid.

I believe this code to be a problem with the purge solenoid circuit. Is that correct?

as to the driver’s seat wire mess. I did find a bit of corrosion and did clean some of it up and will go back to do some more. But in the mean-time I bypassed this connection to illuminate it as a possibility.

At this point I’m going to keep looking at the wiring. But what I need to know is what the code means. If it’s a circuit code, I would expect that a crack in the gas cap can not cause this code. Or am I wrong. Is a bad purge valve (located under the hood) a possibility. And very importantly, should I expect the purge valve to click when voltage is applied? And are there any tests that I can do to narrow it down. Thank you all very much. I fear that some bad advice has made me buy 3 purge valves from a junk yard and, now 2, brand new ones. None of which clicked. I suspect that they are not supposed to.

 

The EVAP Vent solenoid shares the 12v fuse with fuel sensor, P0446 Evaporative Emission Control System Vent Control Circuit Malfunction

EVAP Purge Valve doesn't, its gets 12v from PCM relay usually

Never mind on the C309 connector for the P0443 code, Purge Valve solenoid is in the engine bay in 1999

 

Well I was able to find the diagnostic procedure for troubleshooting this code in my research and after following the steps, came to the conclusion that it’s the PCM. Now I know that replacing the PCM isn’t as easy as running to the parts store. Can anyone tell me what I need to be mindful of when finding a PCM. I think I need to also acquire a PATS module from the same donor if used. Is there anything else. Can I get a new one and a new PATS?

 

You need the PCMs part number
YL5Z-12A650-XXX

The XXX is what you need to match

YL5x = 2000 Ranger
12A650 = PCM part number in ALL Fords, still used in 2023
XXX = the firmware, i.e. EGR, Auto or manual trans, emissions, knock sensor, regular or flex fuel, ect..............
If getting used then you just need to match the year/ranger, then transmission type and regular or flex fuel

Check on the Forscan Forums
Forscan is a Ford software interface that can often "re-marry" 1999/2000 PCMs and PATS modules, but it can for sure program more PATS keys

Yes, if you get used PCM and PATS module from the same Ranger WITH at least 1 working key, you can also get its ignition key cylinder and replace yours so the "working" PATS key can be used in your vehicle

 

Holy Crap RonD. As if my tiny little brain needed more stuff to play with. I’m about to click the “Buy” button for a vLinker. This software looks like what I was sure must be available given today’s technology. I might be glad I didn’t spend $1000+ for a good bi-directional scan tool. I don’t suppose this software could replace a bad evap purge valve driver? Is that asking WAY too much?

Once again, thank you sooo much for the very valuable information. If you’re ever in San Diego hit me up first and I’ll buy you a beer, or a sarsaparilla, or whatever you like to drink.