I am trying to figure out where the IAT wireing is located on the 2002 Fords. *Just behind the air filter box there are 6 wires that are numbered 1-6 on the back and A-F on top. *I'm almost positive that 2 of those wires are for the temp. sensor, but can't find any info. on which wires they are???
Any ideas?

I assume you are looking for the wires leading to the intake air temp sensor .not sure off the top of my head but can check at work tommorow if needed.Anyreason why or is it top secret stuff http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/tounge.gif

HEHE *No top secret stuff here. http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/tounge.gif *Just looking into modifying to read as though it's drawing in colder air. *Don't tell my dealer though..... http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/wink.gif
Would appreciate it if you could check for me.



Last edited by phazerhater at Sep. 09, 2002, 8:38pm

can doo are you looking for the wire colors or location to tap into that is not to noticeable http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/exclamation.gif

Well, on the bottom of the wiring loom they are numbered 1-6 and on the top of the plug is it lettered A-F. *If you could get me the correct number or letter for the wires, I will be set.
Much appreciated! http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/smile.gif

"The IAT sensor:sends the PCM a signal indicating the temperature of the air entering the engine.
It is incorporated into the MAF sensor and is repaired as an assembly."

What are you looking to do?
That input has little (if any) effect on the fuel strategy after the vehicle is in "closed-loop".
The Fuel System Monitor will adjust the fuel trim system to your add on. FSM is used to compensate for variability in fuel system components due to normal wear and aging, so all I see you doing is making the PCM think the IAT is old or dirty.
"During closed-loop vehicle operation, the fuel trim strategy learns the corrections needed to correct a "biased" rich or lean fuel system. The correction is stored in the fuel trim tables. The fuel trim has two means of adapting; a Long Term Fuel Trim and a Short Term Fuel Trim. Long Term relies on the fuel trim tables and Short Term refers to the desired air/fuel ratio parameter "LAMBSE". Both are described in greater detail in this section under Powertrain Control Software, Fuel Trim. Input from the ECT or CHT, IAT, and MAF sensors is required to activate the fuel trim system, which in turn activates the Fuel System Monitor. Once activated, the Fuel System Monitor looks for the fuel trim tables to reach the adaptive clip."
Your HO2S are the base, the PCM/Fuel system world revolves around the HO2S.
Let me know if I can help, Chris

MAF/IAT

'doc, I was told of a little trick. *
When cold air comes in through the intake, the IAT sensor has a low resistance value, and when hot air enters it gives off a high temp. resistance value. *"Supposedly" all you need to do is take the value the sensor will be at when operating at hot levels and use a resistor value that matches, instead of waiting for it to heat up and send the ECU the high resistance value which will then advance the timing, you put the resistor in the sensor harness and then the ECU will always be recieving a high resistance value there for making the computer advance timing. *
Would this not work? *It seemed to make sense to me, but I am no expert by any means in this area!! http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/wink.gif

toydoc has more info in his post than I could get today(had a dentist app)that ate up my lunch.It should be the pnk/blk wire on the end #6 of the maf conn.not sure if I would try to mess with this or not for what little gain you might get .routing cold air to the box would be a better idea IMHO that`s why open element air filters are not on race cars to hot under the hood.

"When cold air comes in through the intake, the IAT sensor has a low resistance value, and when hot air enters it gives off a high temp. resistance value. *"Supposedly" all you need to do is take the value the sensor will be at when operating at hot levels and use a resistor value that matches, instead of waiting for it to heat up and send the ECU the high resistance value which will then advance the timing, you put the resistor in the sensor harness and then the ECU will always be recieving a high resistance value there for making the computer advance timing. *
Would this not work?"

How about we get you on the right track with what you working on first and go from there. The IAT is a thermistor not a resistor. Thermistors are devices in which resistance changes with temperature. The electrical resistance of a thermistor decreases as the temperature increases, and increases as the temperature decreases. You should also know the input signals do not work off the 12 volt system. Thermistor-type sensors are considered passive sensors. A passive sensor is connected to a voltage divider network (5 volts) so that varying the resistance of the passive sensor causes a variation in total current flow. The varying resistance affects the voltage drop across the sensor terminals and provides electrical signals to the PCM corresponding to temperature.
Can you bump the timing by making the IAT input a set resistance spec? Maybe, but I don't think so. I think it would also trick the PCM the wrong way with the timing (less hot).

Toydoc, I had forgotten you worked at Ford. I hard a guy come in today with the $7.00 halogen bulbs in his hand out of an old contintental wanting to now about watteage etc... The bulb had a voltage 14.0 and a wattage (I forget) rating on it. He wanted to know if he could use a standard "peanut" 194 bulb. I told him he could and it probably would not be as bright. He went on to tell me all about the different color filaments ie: green, blue brown etc... an they all had different wattage ratings. I had nver heard of such a thing before. If a bulb is burned out I just replace it I told him. Kevin

IMO, I dont think that is the way to go. That PCM is programmed to keep the engine running at peak performance all the time. Basically the PCM's main job is to save the catylist.The PCM is no dummy,if the values of the CTS and IAT are off considerably during start up,ol' FRED knows that and will throw the MIL on. The thing to do is find a performance shop that has flash capabilities and a dyno.

Possibly this has worked for some guys,I dont recommend it.

definition of FRED...fully rational electronic devise *http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/wink.gif

Boy toydoc, you realy know how to baffle a guy with BS!!! http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/tounge.gif
Just kidding, thats enought to convince me to skip it. *Thanks for all the info. guys. *Like I said, I don't know much about all this new fancy computer crap in the new rigs. http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/wink.gif