Codes not adding up

abrad

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No reading probing pin 1-2??? There must be something, either 0 ohms or open-circuit; which is it? Where are you reading that ~20 ohms. When you probe 1-2, you are probing the pins of the sensor itself, harness disconnected, correct?

I am disagreeing with above post. Resistance readings on the IAT sensor are quite easy, meaningful, and accurate if it is a simple thermistor; which think it is.
Ah, I was reading the harness, which is where I thought you had meant. I’ll check again in the evening
 

grcauto

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No reading probing pin 1-2??? There must be something, either 0 ohms or open-circuit; which is it? Where are you reading that ~20 ohms. When you probe 1-2, you are probing the pins of the sensor itself, harness disconnected, correct?

I am disagreeing with above post. Resistance readings on the IAT sensor are quite easy, meaningful, and accurate if it is a simple thermistor; which think it is.
Why are you so concerned with the IAT? That input has a small effect on the fuel trims and that's about all.
What problem are we chasing again?
When we get off track the post can become convoluted.
 

billr

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Yes, the IAT has a relatively small affect on fueling, but that sensor is part of the MAF assembly, even shares a ground with the critical MAF sensor. And, I think the OP was reporting earlier that the IAT was off; seemed to seek 97F no matter what. I feel there is a problem in the MAF/IAT assembly wiring, do you agree? So, I am trying to troubleshoot the IAT function first, as it is much simpler system. We may even find it has a bad ground, and fixing that fixes all...

If we do have to go after the MAF function, do you have any info on that? From the "+/-" labeling of the wires I am guessing this is an analog DC signal, but have no idea if it is V or I, or what range and calibration.
 

grcauto

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I'm lost. I don't even know what the problem is anymore nor everything that has been done.
Has the sensor been replaced? Unplugged?
 
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