Name that sensor...

[David Pendleton]

Hello all.



What is the sensor mounted on top of the airbox on the 03 Rams?



Thanks.

 

[100 Proof]

IAT sensor I believe.



100 Proof

 

[David Pendleton]

I don't know what IAT means? Can you explain?



Thanks.

 

[Matt400]

Inlet Air Temperature sensor and if your not careful on how you oil a reusable filter it can become contaminated sending the ECM a faulty input.

 

[Matt400]

I better correct myself here and get a little more technical.



The one you asked about is actually the Inlet Air Temperature/Inlet Air Pressure sensor so its 2 sensors in one.



I would bet that the IAP function works like a MAP (Manifold Absolute Pressure) does on a non turbo charged motor providing the computer with altitude data.



There is also an Intake Air Temperature/Manifold Absolute Pressure sensor mounted in the intake.

With the intake being pressurized by the Turbo the MAP portion of that sensor may not be as accurate in calculating altitude so they added IAP to the IAT.

 

[cpizz]

Can the IAT/IAP by the air filter be fooled or changed out for a different one? Wouldn't this help to get more fuel to the motor if you could fool it?

 

[Matt400]

You will get more HP per dollar IMO with any of the fueling boxes than trying to mod that sensor.



I know some gasser guys move the IAT to a cooler spot and that changes timing for a little more HP. Or also I have heard of adding in a resistor that will tell the ECM its cooler than it really is.

 

[cpizz]

I was just wondering. I don't know if you notice. But in the morning when the engine is cold; the truck is definitely more powerful and responsive. As it heats up, it is less responsive. It seems like it loses some torque. Thought maybe there was some way to trick the ECM into thinking it was colder than it is. I have the Edge EZ, but you can still notice this scenario with it on.

 

[Matt400]

There is an interesting thread here on this subject but on a gas engine. It could also apply to the CTD. I do have a wire diagram so if you wanted to give it a try I could tell you what wire to put the resistor on out of the 4 wires on that connector.

 

[cpizz]

Thanks for the info. Matt400! I'm going to look for a resistor. I would like to know what wire to put it on. Do you notice what I was talking about in the previous post?

 

[Matt400]

Originally posted by cpizz

Thanks for the info. Matt400! I'm going to look for a resistor. I would like to know what wire to put it on. Do you notice what I was talking about in the previous post?

On mine the wire to fool would be the Violet with White stripe.

That is the one the sensor is sending data to the ECM.

Your 04 may be different.



FYI- the other 3 wires on mine are:

Gray with Brown stripe

Dark Blue with Yellow stripe

Dark Green with Yellow stripe



I haven't noticed a decrease in performance with outside temps cuz when its cold out I am usually not into the throttle too hard anyway.



It will be interesting what you find...

 

[bpenrod]

If you fool it too much will the grid heater run longer or constantly? Not sure where the heater takes it's cues from.

 

[Matt400]

I doubt the grid heater looks at that one, if it did you would see the heater running all the time as the engine pulls in cold winter air.

The grid heater probably looks at the IAT that is also part of the MAP in the intake manifold and maybe the CTS (Coolant temp sensor)