6speedsd
New member
Been trying to diagnose a low boost/shift schedule issue I've had for some time now. Had AE hooked up the other day watching the typical pids (map, EBP, mgp, iat, etc). While driving I noticed my IAT1/IAT2 temps were vastly different. Upwards of 20F at times. BUT the kicker is that IAT2 (in the manifold) was the one running so much cooler. IAT1 is in the intake ductwork were a MAF would be on earlier trucks correct? If that's right, then shouldn't that one be reading colder, considering its drawing cold air in straight from outside? I know the one in the manifold is reading air that's passed through the IC, but shouldn't there be some heat soak from a hot engine? Temps were in the 20's that day, and during running conditions other than idle, IAT2 was reading not too far off outside temps, but IAT1 was anywhere from 10-20F higher. Both sensors are new as of a few days ago. When unplugged, IAT2 defaults to like 300F, and 1 defaults to something like 58F....is that normal? Why default to 58? Starting to wonder if I have a wiring issue to 1.
And I guess I should ask how much does the PCM rely on info from IAT1? I know it relys on IAT2 a good bit, but wasn't sure about the other.
Truck in the sig...05 model. Want to say April 05 but would need to double check. Where was the switching point from MAF to IAT? Airaid intake on this thing by previous owner....wondering if it was supposed to be MAF being early 05, and was switched for whatever reason to IAT....
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And I guess I should ask how much does the PCM rely on info from IAT1? I know it relys on IAT2 a good bit, but wasn't sure about the other.
Truck in the sig...05 model. Want to say April 05 but would need to double check. Where was the switching point from MAF to IAT? Airaid intake on this thing by previous owner....wondering if it was supposed to be MAF being early 05, and was switched for whatever reason to IAT....
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