IAT1 sensor reads 20*+ higher than ambient

[DSMtuned]

2012 F-150 3.5 Ecoboost.


On my SCT Livewire, I'm constantly monitoring IAT1 (intake temp just after the air filter) vs IAT2 (post intercooler temp) to see how well my intercooler is cooling the intake charge.

Recently I've noticed that the IAT1 displayed on my Livewire was high when compared to my ambient air temperature display on Sync by a 3-8*. I thought it was kind of strange, but mostly ignored it. I just went on a week long trip with my camper and spent lots of time driving around where we camped and noticed a larger disparity between IAT1 and the ambient air, with them being 10*+ different.

Well today I towed home about 3 hrs in the mountains and found that my IAT1 got even further from my ambient air temp display on my Sync. Now these are 20* or more different, with the IAT1 being high. Do you think this indicates a failed IAT1 sensor? The ambient air temp makes sense for the weather.

Another reason I know IAT1 is wrong is because when I am deep in boost, my IAT2 falls within or a degree or two of IAT1 and I even saw the IAT2 BELOW the IAT1, which should never happen with the IAT2 being post intercooler. These are usually 10* different when at full boost.

I hate to throw parts at the truck, but this sure seems like the IAT1 sensor on the air cleaner is going bad. I can't find a way to test it in the service manual or wiring manual. The part number is CX2420 and is labeled as a MAP sensor, but I think it really is just is a temp sensor.

Thanks.

[mJolnir]

I think thats just heat soak affectin the iat reading

[DSMtuned]

I think thats just heat soak affectin the iat reading

The sensor we're talking about is pre-turbo at the air cleaner, so it should be as close to ambient air as possible.

I was mostly just wondering if anyone knows how these fail, i.e. reading low or reading high.

[mJolnir]

it happens to me even on NA cars, IATs go up while the car is not moving and then they go closer to ambien while the car is moving