I have a CEL with the 0401 trouble code, which is for the Intake Air Temp (IAT) sensor.I'

I opened up my Haynes manual and the IAT is shown to be mounted on the top of the airbox (it doesn't get any more accessible than that). However, when I popped my hood and looked, the sensor isn't anywhere near where the manual illustrates. I can't find it to save my life.

I'm very confused. How can I trip a code for something that isn't there? Can anyone explain why the Haynes manual shows it in a place that isn't accurate? Any idea where the IAT sensor actually is?

Thanks.

 

It's down on the bottom.

 

as far as i know 97 and up have the iats on the intake tube itself not on the filter box in order to change it you need to remove the filter box to have access to it but it seems its the same thing i'm expecting to receive my today

http://forums.maxima.org/showthread.php?t=510523

 

the sensor is almost directly under the MAF. It's on the snorkel hose as it curves to the bottom of the air box. Take the top of the box off and you should see it. You should be able to see it look from the front of the car as well.

 

shall i crawl out of bed and take a photo? not sure mine would help. mines just hanging around in the engine bay cable tied. its just a connector with a black thin piece of plastic.

 

There are only two sets of wires that go to the intake box. One set is for the MAF, the other is for the IAT. Just keep looking around until you find that wire.

 

i got the iat sensor code from my CEL, but i cant figure out why. i have a CAI, and i just recently connected my iat sensor to the intake but the light didnt go off, what is my problem?

 

still need a pic?

 

I tripped the same code. I think mines fell into my engine bay. lol Since the temps will warm up tomorrow, I will get in their to locate.

But as everyone said, it plugs directly into intake airbox (or aftermarket filter for others). Mines came out as there was never a connection for the sensor in the crappy filter I bought.

 

if you to a local pep boys or auto zone ask one of the mechanics there am pretty sure they will find it for u just ask them for help

 

from the inside of the upper air box (above the filter) there is a small thing that is protected by a round piece of plastic. If you look closely, it looks like a small electrical resistor encased in glass. That's because it basically is. It's called a thermistor, and works by temperature changing it's ability to resist current.

 

in this thread i posted pics of the 2 different iat available for our cars the one that goes on the airbox or the one that goes below the maf

http://forums.maxima.org/showthread.php?t=510523

 

Here is the intake snorkel removed from the engine. The red box designates the area of the next picture.


Here is the hole where the IAT sensor is.


[/thread]

 

weird, the '96 Maximas must not have had that...because I just ripped the entire stock intake out and there was nothing in that spot you pointed out.

 

for the 96 its located on the actual air box it self for the 97 its on the snorkel piece

 

According to JWT, Intake Air Temp (IAT) sensor isn't really important. I just attached it near the MAF and that's it. No codes, nothing!

 

first is either on the airbox or on the air tube/track and it does trigger the cel light and the code is

0401
Diagnostic Trouble Code 0401 points to a problem with the Intake Air Temperature Sensor. The IATS is mounted in the engine air intake duct, downstream of the air cleaner filter. It detects intake air temperature and transmits a signal to the Engine Control Module. The sensor uses a thermistor, a resistor with a value which is inversely proportional to temperature. The IATS is not directly used to control the engine. It is used only for diagnostic purposes. Therefore the engine should start and run normally, even with the Malfunction Indicator Light on and DTC 0401 stored.
This malfunction is detected when ...
a) An excessively low or high voltage from the sensor is detected by the ECM.
b) The signal from the IATS is inconsistent with the signal received from the Engine Coolant Temperature Sensor.
Possible causes include ...
- Harness or connectors (The sensor circuit is open or shorted.)
- a faulty Intake Air Temperature Sensor
The IATS resistance values should be ...
- at 14 degrees F, 7.0-11.4 Kohms
- at 68 degrees F, 2.1-2.9 Kohms
- at 176 degrees F, 0.27-0.38 Kohms
For further information about the Intake Air Temperature Sensor please refer to the Chilton repair manual (page 4-16) or the Haynes repair manual (page 6-11).

 

hahah autozone and pepboys 'mechanics'...if they were mechanics they wouldnt be working at autozone/pep boys

you may get away with that on a max, but on some cars the EGR monitor uses the IAT to see if the EGR is funtioning properly. so dont think its not importent on every car.



and like everyone else said, IAT is on the tube leading up to the airbox.

 

some cars 97 and up have it on the tube some pre 97 have it on the airbox make sure that if you need to replace it you know which one you need i did that mistake