1999.5 Pathfinder P0505 Code

[jux]

I have a 1999.5 Pathfinder with 215K miles on it (original owner). My CEL has been on for 2 years since I know what the codes were and haven't been concerned. I'm now fixing the issues.

I'm down to one code which is the P0505 code IACV (Idle air control valve). I've already cleared the codes and it came back after 3 drive cycles which I expected. Most posts I see discuss stalling, failure to start or an off idle but I've never had those issues. It starts fine, idles at 750RPM without issue and has never stalled. Not sure what approach to take here besides cleaning the IACV and electrical contacts.

Any help would be appreciated.

[jux]

I replaced the IACV and now the idle is fluctuating between 900 and 1200 and the IACV sounds like it's continually clicking.

Stupid thing is I probably didn't have to replace the IACV but because of the asinine way in which the 99.5 3.3L engine is placed into the engine compartment getting to the IACV is a 3 hours job after having to remove the upper plenum. Who engineers hoses and cable 1 inch from the firewall 6 inches or more from the top of the engine? No way I was taking the chance of the IACV being bad for some reason I couldn't detect and then having to remove the plenum again.

I got everything in after a fair amount of new words I've made up for Nissan engineers, start the truck, runs fine for 30 seconds until the idle comes down and it's like I'm on a coin operated horse rise outside of Walmart.

After 220K miles I think I'm just done with the pathy. Between the constant front end vibration, going through rotors and brakes like I'm single handedly keeping Bendix alive, sway bars, main oil seal bearing, seized compressors, and a myriad of other things over the 12 years I've had keeping me busy for at least one weekend day a month I don't think I've got the willpower to take the plenum off again.

[Slumpert]

You left off the part that Nissan put lots of sharp seams right at that spot so your hands get tore to pieces. I really should have looked for appropriate hose clip tools and I will before I try to pull it again.

[Buzzman]

I replaced the IACV and now the idle is fluctuating between 900 and 1200 and the IACV sounds like it's continually clicking.

This may or may not help, but I just went through this with my 2002 Pathfinder.
It's not the same engine, but maybe the procedures are similar.
In my case, the bad IACV blew the ECM. I had the ECM repaired, as well as replacing the IACV.
To get the idle back to normal after putting it all together, I had to do the relearn procedure.
(The dealership actually did it for me for free). Took 5 minutes.
Maybe your engine just needs the relearn as well.
Hopefully your ECM is still good.

[jux]

Thanks for the advice. In the Hayes manual it details the relearn procedure for the 3.5L but nothing for the 3.3L. I went back and took a look at the service manual for the 3.3L 2K pathfinder and I can not find a relearn procedure in the service manual which agrees with the Hayes manual.

[Towncivilian]

3.3L doesn't have a relearn procedure. Hayne's manual is junk in most cases, get the Nissan FSM: http://www.nicoclub.com/FSM/Pathfinder/2000_Pathfinder/

There is a fast idle cam adjustment procedure described on EC-40 but this should generally not be required.