89’ 22RE: No continuity on FPU wire from ecm harness to FPU VSV connector
 

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I don't see any connections or anything like that in that line. It should be a straight through connection. Your meter should read zero (0) ohms from the FPU pin of the ECU, to the VSV's connector.
Make certain both leads are off the battery before you try to ohm anything at all. It doesn't take hardly any voltage to blow the fuse in your meter on the ohm's system. Double check your meter before any ohm check. Touch the two leads together to make sure the meter is functional. It should read zero ohms when you do. If it doesn't, it could be your meter isn't set up correctly, or the fuse in the meter is blown.

If all is well, but you still get no reading for the wire, start tracing the wire, end to end. Pull it out of any looms it's in, and follow it to ensure it hasn't rubbed enough to break the wire someplace. Any damage to the insulation, you may have found the trouble. Also, as you trace the wire, flex it see if there's an intermittent somewhere. I would start at the VSV, and trace every bit of that wire, end for end. Mark it somewhere as you go to ensure you stay on the correct wire.

Does that help at all?
Pat☺

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My pleasure. I wish you the best of luck. It may not be all that easy, tracing the wire through to it's other end, but it's essential. You did what you could with your meter, determined that wire is open. Now the fun of finding just where starts :D

Just so you know, I'm a radar technician. Have been since 78, I developed the habit of checking the meter whenever using it for any ohm reading. Just a matter of touching the two leads together to ensure a zero reading on the meter. When I first started, it was necessary to do this so you could zero out the meter. The old Simpson 260-5P has an adjustment screw, and before using it, you had to zero out the needle. The habit just stuck with me the rest of my career.

Anywho, let us know how things work out for you :)
Pat☺

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Thing is, the AFM, and the Water temp, are sensors, not switches. Essentially, the ECM feeds both sensors with a single input line, E2, and reads the results as THA, for air temp, and THW for water temp. So, if the voltage to the AFM, or the AFM's sensor itself, are bad, the water temp will be bad. It's a voltage divider network.

Thus, yes, check the air temperature sensor for correct value. You need to put a thermometer next to the sensor, really. In actuality, you can just have a good thermometer somewhere close to check that the sensor's resistance is correct for the current air temp.

When you replaced the water temperature sensor, did you clean the threads thoroughly? It matters a lot. No tape or other form of sealant on the threads when you put the new sensor in? No corrosion of any sort? You should scrub the threads, on the truck, AND an the sensor, with a brass wire brush. GENTLY! You want to make sure there's no corrosion on the truck's threads, and no form of preservative on the sensor's threads. Many companies will put a plastic sealant of some sort on the threads of the sensor to keep them shiny and bright so the customer is happy with them. Just don't sure a steel brush, as it'll damage the aluminum threads on the truck. Even a brass brush can damage the aluminum thread, so again, gently is the word of the day.

Let us know what you find :)
Pat☺

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Was it something I said??
Pat☺