Code P0505 after changing spark plugs..Help

[smancer]

Hi Guys,

I'm new here and I need some help with my 2001 Nissan Pathfinder LE. I recently did a bunch on DIY maintenance on my Pathy here's the order I did it in flush ATF, change differential fluid, change transfer case fluid. Then I changed the spark plugs using the guide that was provided here on the forums (great DIY write up btw), also cleaned the throttle body. Everything ran great for 4 days then the SES light lit up. The truck still drives great I don't notice any misfiring or anything.

Today I made sure all vacuum lines are snug and all sensors and coil packs are plugged in properly, then I cleaned the MAF sensor. The SES light was still on so I went to Auto Value to get the SES Code Read and gave me Code: P0505 Idler Air Control Valve. I believe this is the black round sensor with the blue plug below the throttle body that I had to remove when I changed the spark plugs.

I did some reading on this but I'm not sure what exactly to do. My hunch is that I was supposed to do the Accelerator Pedal Released Position Learning, Throttle Valve Closed Position Learning and Idle Air Volume Learning after I reinstalled and connected my IACV when I changed my spark plugs (I also disconnected the negative battery terminal during the process of changing the spark plugs). Right now the engine idles at around 1k rpm at normal operating temperature which I guess is high since it's only supposed to be 750 +/- 50 for A/T models. So I tried doing the manual learning steps according to the service manual but when I get to the Idle Air Volume Learning which is supposed to adjust my idle to the right setting. It doesn't seem to work, when I get to step 7 and as I hold the accelerator pedal for 20 secsonds the MIL or SES light should be blinking but mine doesn't do anything just a solid light throughout the whole process.

Has anyone experienced this and knows how to fix it? I'm thinking maybe the SES needs to be reset first before I do the manual re-learning steps then it will work and SES will not light up after?

Thanks for the help!

[Towncivilian]

Follow the procedure outlined in EC-58 of the FSM to do the Idle Air Volume Learning.

EDIT: Oh, you tried that. Blah, reading comprehension for the lose. Maybe try disconnecting the negative terminal of the battery for half an hour, then put it back on and try IAVL again?

[351cleveland]

Ignore that last comment. To reset the ses you need to dissconnect the negative battery terminal for atleast a couple hrs, but prefferably overnight, and that should reset your ses.

[smancer]

Ok so the battery thing didn't work to reset my SES and I also tried the suggestions in the FAQ section those didn't work either, so I ended up picking up the cheapest OBD2 Scanner I could find.

What weird is when I scanned it it said no codes but the SES light was still on so I reset the SES with the scan tool. So does that mean whatever I tried to do fixed the malfunction worked that's why there was no code detected? and I just needed to have the SES light reset?

[CanuckQx4]

You are not doing the test for the 2001 model year I believe

The procedure for the 01 is much easier. Its on ec-58 of my manual






Ive never heard of the 2 other tests you mentionned, but now I want to do them aswell lol!

I had this same problem as you with the idle volume relearn until I was told I wasnt doing the 2001 specific way to do it

[CanuckQx4]

Could you actually tell me what sections these 2 tests are in, I cant find them in my 01 Qx4 manual anywhere

Accelerator Pedal Released Position Learning,
Throttle Valve Closed Position Learning

[smancer]

Hmm...I guess if you have the 2001 Service Manual that's what I should be doing. I've been using a 2004 Manual the whole time I guess they changed a bunch of programming stuff since then that's why nothing I'm doing seems to work. I just thought any year R50 service manual will work as long as it's for the VQ35DE.I use an older service manual for my altima also and it seems to work good for me.

Anyways on my 2004 Pathfinder Manual here the 2 other procedures (Accelerator Pedal Released Position Learning,
Throttle Valve Closed Position Learning) can be found on EC-73.

[Towncivilian]

Hmm...I guess if you have the 2001 Service Manual that's what I should be doing. I've been using a 2004 Manual the whole time I guess they changed a bunch of programming stuff since then that's why nothing I'm doing seems to work. I just thought any year R50 service manual will work as long as it's for the VQ35DE.I use an older service manual for my altima also and it seems to work good for me.

Anyways on my 2004 Pathfinder Manual here the 2 other procedures (Accelerator Pedal Released Position Learning,
Throttle Valve Closed Position Learning) can be found on EC-73.

That is why I suggested you follow EC-58 in the PDF file I linked to at the first reply. 1994-2010 FSMs can be found here (2010 is here). You can also find the proper year manual for your Altima here.

[smancer]

Cool thanks! I guess I was too frustrated when I read your first post. I didn't notice the link and I thought any R50 service manual is applicable from 2001-2004.

I'll try doing the right procedure when I have time and update you guys. Thanks!

[smancer]

So my SES came on again today with the same code P0505. Does that mean I have to change the IACV now? Everything is still running normal. Anyone have any other suggestions I can try doing to diagnose the problem?

[CanuckQx4]

Did you ever get this fixed??

My car idles LOW with this IACV error

[smancer]

No, I didn't end up doing anything since it wasn't really causing me any rough idle problems. I just kept on driving with the error and SES light on and didn't reset it with my OBD tool anymore. Then the other week the SES light just turned off by itself so I guess that's a good sign, maybe.

Right now my idle is sort of in range now when I drive for a bit and if it reaches operating temperature. My RPM when in drive is around 850 and then in neutral 850-900, in park around 900ish. So I'll probably just leave it as is so the annoying SES light doesn't pop up.