incoming air sensor

I have a 99 grand voyager and the service engine light came on. I did the check with the key in ACC to check codes and it came up 23 which is possible bad ICA sensor. Where is it at and how do I change??? is it expensive. How do I reset so light goes off. Thanks

This light is freakin me out.
I appreciate all help because I am no mechanic.

Do you mean the IAT or Intake Air Temp sensor? If so it's on the intake manifold and has two electrical pins in the connector. You must have the 4 cyl engine.

You should test it before replacing it. Measure the resistance across the pins when cold then when hot. Should decrease when hot.

Like I said i am no mechanic but the chart I read on the internet called it the Incoming Air sensor. But no one seemed to know what that means!
Is there such a thing?????

So on the other intake sensor I put a regular meter on the conector or the pins on the sensor. Da!!! I assume the sensor..right???

Just checked! I have a 6 cyl.

Only the 4 cyl engine has an IAT sensor so we are back to square one. Your best option maybe to go to a local Autozone and have them connect an OBDII scanner to download the code and reset the light. They will tell you what sensor is bad and it's all free.

Ok now I am really confused! I went to Autozone and he checked the codes and it came up P1491...He said that I would have to take it somewhere and have the entire Emission system checked and didn't pinpoint any sensors??

Why did the car give me a code of 23 and autozone P1491??

Is it safe to drive car with that light on??? Car seems to be running fine.
Those Dealer shops always seem to charge so much.

Thanks

You aren't the only one who's confused. I found many references to MIL fault code 23 on the internet and all state it's an IAT sensor failure. Only a few state it only applies to 4 cyl engines. I can't find any reference to an ICA sensor anywhere. I can't find any reference for an IAT sensor on anything other than a 4 cyl engine. You own a 99 GV which only comes with a 6 cyl engine. :banghead:

Scan code P1491 (MIL code 35) deals with the emissions system. There are Federal regs concerning maintenance on this system. I'm guessing he felt he wasn't qualified to even give advise about it and wanted to keep his job. Specifically, P1491 indicates a failure in the low speed radiator cooling fan control relay circuit. It could be nothing more than a flacky relay. If you don't want to mess with it and your van is running fine then I don't see a problem not fixing it. Just be aware that if the problem gets severe your van could overheat. Confirm the radiator fans are coming on and watch the gauges. Also be aware that if you live in a state that requires periodic emissions testing, an illuminated check engine light is an automatic failure. You'll have to get it fixed before the test. Finally, if you get another failure somewhere you may not know it because the light is already lit.

Why were you getting a MIL code 23? You've got me. Are you sure you read the code correctly the first time? It's very easy to miss read. Most usually get a 12 and a 55 which essentially can be disregarded. 12 = battery was disconnected, 55 = end of test. The important code is in between these codes. If you were really getting a 12...35...55 I can see where you might have mistakenly seen a 23 code. Watch for the longer pauses between the codes. If you read it correctly then I don't have a clue. Maybe somebody else can shed some light.

Thanks for the help....

When I perform the test myself using the key in the ACC position I most definately get 23 55

Why at autozone I get P1491???? that is not even close to a 23

Oh well I will keep an eye on things. So what you are saying is if the fans are working then there should be no problem???? If van doesn't overheat..

Dumb question...should the fans be running all of the time????

If the A/C is on the fans will run all the time. If it's off they will run when the coolant temperature reaches a certain temp (don't remember). Once the temp goes below that set temp, the fans will turn off. They will cycle on and off as the coolant temperature rises and falls.

The codes we are talking about are two different animals. Malfunction Indicator Light codes or "MIL Codes" are the two digit codes you read when you cycle the key. "Scan codes" (also called "P" codes) are up to 4 digits and prefixed with a "P" and can only be read with a scanner. Why the difference? MIL codes are a quick check that gives you a basic idea of where your problem lies. Scan codes give you more specific indications of where to look in the failed system. Most MIL codes equate to a Scan code. MIL Code 35 equates to Scan Code P1491. MIL Code 23 equates to Scan Code P0112 or P0113. This may help: http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/1a/41/40/0900823d801a4140.jsp There's lots of info there on many pages. Look around.

Recommend you crack open the wallet (tough act for me) and buy a Haynes or Chiltons maintenance manual for your van. ($15-20) They can be had at about any parts store or even Amazon.com. I think I've seen them in WalMart.
Might clarify some issues. Even if you don't plan on doing your own maintenance, it will give you some idea of what is going on so you can explain it to a mechanic without having that "deer in the headlights" gaze or better yet, keep you from getting snookered.

Ok I checked the fans and this is what I found.

Fans DO NOT come on when air conditioning is turned on.

Fans DO NOT come on when car is hot!

So does this mean the relay is bad?????

Car doesn't overheat on small trips but I know this needs fixed now!
Is this something I should attempt??? Where is this relay located ??

Thanks for all the help.

Ok, I called dealer and they said it sounds like Radiator coolant fan relay.
Said it would be 200 bucks for them to do but part is 70 bucks.
They said it was a job I could probably do if I could get to it. Said it was located down by radiator on drivers side. I took off air filter and followed wires from fan into a bundle but found no relay????? Any help???

It's not actually on the radiator is it?? On the block??
Help??? Also Napa sells for 60 bucks