Hi Daniel,
Here are the code descriptions and possible causes.
-40 for any intake or coolant temp sensor is a default reading when there is an open in the circuit. So it is either the sensor, wiring, or PCM has an open.
I would suggest starting with the IAT sensor issue prior to the IAC. Due to this being affected by your open in the temp sensor it may just be one issue. However, the IAC code is a circuit fault so you may have two issues. It is unlikely to be the PCM so just make sure you ohm out wiring first.
https://youtu.be/nksLy9MS0IQ
https://www.2carpros.com/articles/how-to-check-wiring
https://www.2carpros.com/articles/how-to-use-a-voltmeter
Let me know if you need more detail on how to do these tests or what you find and we can go from there. Thanks
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May 5, 2019 at 8:39 PM
