P0505 Code Solution on 2001 Maxima

Hi

I am having the service engine soon light on and the code reads P0505 Idle Control system malfunction. I have already replaced the idle air control valve a few days earlier since the vehicle was stalling at low rpms and thats what the dealer told me to do. Now that problem does not occur but the vehicle when on idle causes rpm to go high like 2000 and while driving the vehicle is surging even though i take my foot of the accelerator pedal.

Any help on this is greatly appreciated.

Thanks

[NissanTech]

The dealer fail to tell you that the auxiliary air control valve (AAC/Valve) you replaced, may have also damage the Engine Control Module(ECM).
Usually the fail part is the step motor inside valve, when the motor fails it overheat the system damaging the ECM. Unfortunately the only solution is replacing the ECM.

Thank you so much for your reply

Also I should have mentioned earlier that the problems I am facing now, namely the high idle and the surging during driving were the first things to occur before even I replaced the IACV. At that time the check engine light was not on. after driving for around a day the check engine light came on and in fact the next morning the high idle and the surge just went away ! But then the car started stalling at low rpm around 1000. Thats when i took it to dealer and diagnosed the IACV problem. After the IACV was replaced the car is now went back to the first problem high idle and the surging during driving.

Do you think the above additional information gives you more insight ?

If as you said the ECM is gone bad, should not Nissan replace that since its went bad without any thing being done to it.

Your reply will be greatly appreciated

Thanks

[NissanTech]

You should call Nissan Consumer Affairs (1-800-647-7261), or have your delaer check for warranty. The ECM is a powertrain item and should be cover under the porwertrain warranty wich is 5 years/60,000 miles.

Hi

thanks you very much for your reply. If the ECM is gone bad, will it be possible to replace that ECM with one from a similar car like for example using a salvaged part ? What will be the steps to do this ? Will i have to involve the dealer to do reprogramming of it ?

Thanks

Hi

An update on my problem

I took to a dealer and he told me probably the ECM need to be replaced. This will cost me lot of money. I took it to another dealer and he performed an IACV learning procedure. He thinks that it is not a problem with the ECM. The car seem to idle better but stil not normal. But the problem of surging during driving even though i take my foot of the accelerator pedal has gone away.

Only today it started to behave like before i.e stalling if I take my foot of the accelerator on low rpms. THE Service engine soon light is still ON with the P0505 code.

Do you think if I replace the ECM all these problems will go away ?

Anxiously awaiting your reply.

Thanks

[NissanTech]

I will need to run some test to tell you with certainty that the ECM is bad, but most likely that is the problem. The other unlikely possibility is a bad harness, the wires (4) from the ECM to the Valve. About your question on a used ECM, yes is possible. Now, is not necessary, but the newest software program should be install in the used ECM and the key will need to be reprogram as well.

HI thank you so much for your reply.

Again this morning the car was dying with very low rpms. I had to keep the engine running by pressing the accelerator. I noticed that there is a screeching noise when I am pressing the pedal to keep the engine running. This seem to be a new problem ..So i have just parked the car for now. I will probably take it to the dealer soon.

ALso just to let you know that its cold in the past 2 days here. The temperature this morninig was around 14F. Does that make a difference ?

Thanks again

Talha

Hi

I am trying to get a replacement ECm for my maxima. My maxima is 2001 without Traction control and automatic

Will any computer (ECM) from the same model and year and without Traction control and automatic will work ? Or do I have to get the same A56 ** number which is printed on the ECM that I am replacing?

Reply is much appreciated

[NissanTech]

I check the diagram for your car, and it seems that there are a few wires that are different with the non-traction control unit. If you use the non-traction ECM, the engine light may come 'ON' and the traction system will not work properly.

Hi

Thanks for all your help in solving my problem. I did replace my ECM with another used one from the same car and options and the problem of low idle/stalling is solved and the car is working great.

One minor thing that is still concerning me is that whenever i put the car in P or N, it idles around 1000 rpm instead of the recommended 750. When in D gear and completely stopped it idles around 750. As soon as i put it in P or N it increases the idle to 1000. I am not sure if the dealer did not perform the idle learning procedure or this could indicate something else ? Your opinion is highly appreciated.

Thanks

[cesario2174]

i need to replace the ecm on my 2001 nissan maxima can some one tell me where is located

[jmkees1]

2001 Maxima...
I had the P0505, sent the ecm in for repair & bought a new iacv. It's been a month since I started with this issue, finally got my ecm back, etc...
I remember finding something about the coolant supply to the iacv, but don't remember exactly what was said, & now I'm having trouble finding it again. If you have any info on this, please let me know asap. I need to get this thing on the road again!