I have a 2000 nissan maxima that recently had a CEL recently with IACV : high idle. So I purchased an IACV with a throttle body from one of the org members. I had my mechanic just take off the sensor and replace it with the one I had purchased off the org. 100 miles later, same CEL light. I drove on it for another few hundred miles.

Yesturday, I decided that I wanted to finally get the problem corrected. So me and a friend took apart the entire intake system all the way to the TB.

After removing the TB, i took off the 2 sensors in the back that have a spring on the other side, and the IACV sensor and put it on the other throttle body that I got when I purchased the IACV from the org member.

We put the antifreeze lines back on and the sensors back and got everything back the way it was.

After turning the car on, the rpm shot up and would no go down even on idle.
My idle was at 1500 rpm and would not go down. I initally thought that the cables got tangled or were too tight. They were not, they were just fine. Then I thought that I did not connect the sensors correctly, checked them, they were fine.

What gives?
Now when I drive, no need to gas, the car just takes off on its own.

Ohh and its not the MAF sensor, it works fine.

thanks for the replies

 

Have you tried the idle relearn procedure? http://www.technosquareinc.com/350reset.htm
Here is a DIY for ECU and idle/pedal learn.

 

thank you very much. I hope this helps

edit.... wait thats for 350z, is it the same for a 2k maxima?

 

http://www.technosquareinc.com/maxima.htm
Check here and good luck. I don't know for sure, but my guess is that they reset the same.

 

Could this problem also exist from a vacuum leak?
I did not make a new gasket when I changed it, where does this gasket go and what is the part number? Then again I didnt really take off the entire IACV just the sesnor and then replaced it

Thanks for all the help.

 

I replaced the IACV and the TPS, still have a high idle and still have the CEL. I took my 2001 to my Nissan certified technician friend and he checked and cleared the 505 error CEL, but it came back on.

He said that when the IACV is replaced, it somehow fries the ECM. The 505 code I have is a fired ECM. He's going to get it replaced at Nissan under the 8/80 Federal Emmissions Warranty.

 

Yeah, I heard of that too.
Intresting thing is, the CEL went away after I did this all and reseted the sensor but the car is undrivable

 

Its funny that when a newb asks a question in another thread, he gets flammed, but when a not so newb asks an expert question, i get one or two simple answers. Where the heck are the experts?

 

Because it's more fun to flame a nOOb like me, and anybody can talk s**t but your question requires an intelligent answer from someone with automotive knowlege, not just a degree in lipflap.

 

hehehe i so agree. thanks for all your help thought. I think its us, the newbs that really make maxima org the successful site it is today.

 

If your idle rpm is below spec, and you have done the accelerator pedal position learing and the idle air volume learning, then its time to take it to a dealer and let them use consult to perform the idle air learn.

I had the idle rpm speed too high problem with my 2002, replaced the throttle body and tried the do it yourself way for idle air volume learn, but it didnt fix it. Only the dealer could force the ECM to "relearn" the correct idle rpm speed.

 

Yeah I heard that too. However the 2002 idle learn did not work for my 2000 as I thought that it would not (using technosquare instructions)

 

Wait did the 2000 have the electronically controlled throttle like the 2002 does? I cant remember.

 

i believe so. it has an iacv and then tcm sensor. and is controlled by the ecm.

 

No the 00-01 still have the throttle cable. The 02-03 have the electronic throttle.

 

how can you reset it?

 

there is a writeup in the how to sticky...

 

Yeah for a 2002 but notice I have a 2000

 

According to my mechanic, he says that I damaged the TPS sesnor.
How can I have damaged the sensor and would it be doing this?

He showed me that once you turn the TPS sensor, the rpm increase but it hesitates.

 

UPDATE:
I took my Maxima to Nissan yesterday to get the CEL fixed. My buddy, the tech, replaced the ECM and showed me the inside of the bad ECM. He said that when the IACV went bad, it sent a voltage spike to the ECM and blew up one of the microchips on the motherboard...pieces were everywhere.

My Maxima is running great now. The CEL is gone and the idle is perfect.

 

thanks you guys. I just ordered an entire throttle body and computer from a salvage yard.

 

Good luck, hope everything works out for you!

Also, make sure it's the correct ECM...I believe there are 4 at least different ones?

I think they are:
Auto w/ traction control
Auto w/o traction control
Manual w/ traction control
Manual w/o traction control

But the tech said there are different ECM too, but I didn't check into that too much since he knows what he's doing...he looked on the computer and grabbed one from the parts dept. that worked.

 

i had the same code took it to the dealer there was nothing they could do but replace the throtle body it cost almost 800.
Good luck