Well as some of you know, i got my injectors, throttle body, fuel system treated last night at Nissan, and just for fun i plugged in my OBDII scanner on my ride home, and i got a P0505 code (Idle Air Control System). The CEL is not on in the car, and when i pulled up the code, the light came on yellow, and not red. Im guessing read means it's in immediate need of replacement, and yellow means it was triggered but it's not constant. I then reset the code. Im guessing it was triggered by the cleaning Nissan did... I heard of people on this board who's ECU was burnt cause of the IACV. Should i be worried?

Thanks

 

It seems that when some people mess with the throttle body, they trigger the bad symptoms with the IACV. Reset it and see if it comes back, then you can worry.

 

if the problem was caused by the dealership doing the fuel system cleaning...take it back to the dealership.

 

is your idle any different than before? If not and the code doesn't return I wouldn't worry about it. They probably just triggered a code after cleaning out the TB...

 

Hope you don't mind me asking but, roughly how much was the cost? Do you overall feel any difference when you start the car? The reason I'm asking is, whenever I start my car in the mornings, there's all sorts of crap coming out of the exhaust. It onky does that in the morning when I first start it.I have 185,000 miles on my car but it runs well since I maintain it very well. I've had most of the work either done by a performance shop, or an excellent mechanic.

 

Black smoke in the morning could be caused by oil slowly dripping over the night in between valve guides/seals or even a PCV system malfunction. Different issue so a flush wouldn't do much. You can still drive that for many many more miles don't worry. Perhaps 100K minimum, till it will get worse and start fouling plugs.

 

probaly an ISC system code. You do have to go back and ask the writer to pull up your workorder and ask him to seee the printout of the idle air relearn that says CMPLT in top right corner. That means he did the idle air relearn. You have to do that after every Throttle body service. You will have some other issues. And if no paper stampled ask them to relearn it and show you a printout after. That is bad for that tech as it is a comeback!

 

The car feels AMAZING as i stated above. My car roughly has 135,000miles on it, and she's running a lot better, gave her back that step she once had. It only cost me 110$ Can plus taxes to do the cleaning with the products included. I was very happy, i think you'll be too!

 

what year is your max? ? i have seen some max's where the idle must be reset after doing the service. i think i have only seen this a couple times on the 3.5l cars. this could have been a stored code as well. even though the mil was not on when you scanned it the ecu still has the ability to store, and let stored codes be read without the mil light on. wouldnt worrie to much unless your idle sucks.....

 

didnt see this post before i wrote mine....... oops. thats what needs to be done though

 

Ya it's a 2000 Maxima. Before bringing the car in i checked for codes, and there were none even store. When i got my car back, there was the P0505 code, i thought it was cause of the cleaning so i used my OBDII scanner and reset it. I checked yesterday and the code is back! Should i bring it back to Nissan?

 

Well i reset the code guys and the P0505 came right back on (although no CEL is shown on the dash)

would it help if i did this?

PRE-CONDITIONING
Before performing Idle Air Volume Learning, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
+ Battery voltage: More than 12.9V (At idle)
+ Engine coolant temperature: 70 - 99°C (158 - 210°F)
+ PNP switch: ON
+ Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)

Turn ignition switch ON and wait at least 1 second.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PRE-CONDITIONING
(previously mentioned) are in good order.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Start the engine and let it idle for at least 30 seconds.
7. Disconnect throttle position sensor harness connector (brown),
then reconnect it within 5 seconds.
8. Wait 20 seconds.
9. Make sure that idle speed is within specifications. If not, the
result will be incomplete. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.

There is a picture of where the TPS is. If someone can host it I can sent it to them, otherwise PM me your e-mail and I will send it to you, unless you can attach pictures in PMs.

 

If there's no MIL would Nissan even care? Also you're liking the way the car is driving, correct? No idle problems?

 

I do like the way she's driving, but sometimes when im driving on the highway, going 120km/hr (75mph) i'll be reving at 2,600rpm and then other time's i'll be closer to 2,450rpm's. (it's always been like this). I've also noticed that in traffic, my car will accelerate to 25km/hr (15mph) without even touching on the gas, is that normal?

Anywho when i sent my car to Nissan, i had no codes stored at all. On my way home, i checked and i had P0505. I used my OBDII scanner to get rid of the code, and it came back, so something's wrong right? i mean even though the CEL is not on, my code is stored in the ECU, and it came back even after resetting it.

 

Something may or may not be wrong, but I wouldn't take it back to Nissan and give them an excuse to adjust your wallet while they look over the car. I don't think they're going to anything for free unless you can prove it's a result of their work especially if there's no MIL lit. It's against their religion.

As for a change of revs at cruise, that could depend if your torque converter is locked or not. If you have a manual transmission then never mind. As for accelerating without touching the gas, it doesn't sound right. Did it start after Nissan service or did it always do that?

 

1- So ya, i just called Nissan, and they said that it could either be the Valve that might need to be replaced or the ECU is not grounded properly, something along those lines anyway. He said the Idle relearn should have been done when the car was being cleaned, and he doesn't see a relation between the code and the cleaning that was done to my car. He then proceeded to tell me to bring the car in so he could take a look at it. What should i do?

2- I have an automatic max, and i just noticed the car accelerating like then when i was in traffic one night

Last thing i need is to be ripped out of a couple hundred $$$

 

As long as you're happy with the way the car drives and there's no light, don't let them near your wallet. The ECM ground theory sounds pretty flimsy.

 

I guess i'll start off by trying the idle relearn, and i'll unhook the battery tonight
i need your help though
what's this mean? + PNP switch: ON

and also what does this look like? 7. Disconnect throttle position sensor harness connector (brown),
then reconnect it within 5 seconds.

thanks a lot
joey

 

PNP switch on means you have to be in park or neutral. As for where to find the connector, I'd have to look.

 

let me know if you can please.

it's greatly appreciated

 

the harness connects to the throttle position sensor on the throttle body

 

Let us know your progress. Right now I'm predicting the worst scenerio but I won't get ahead of myself.
1) Try the idle relearn manually, if that doesn't work I would try to convince the dealer to do idle relearn w/ Consult II since they triggered the CEL in the first place.
2) If that doesn't work, test to make sure the IACV is functioning - there are many ways to do this. Let us know of you need help.
3) If IACV is faulty, replace it
4) If the CEL remains after IACV replacement (after reset and another relearn attempt), your ECU is more than likely shorted. If this is the case, it's not a waste of money to replace the IACV even if the ECU is blown because the IACV malfunctioning is the reason the ECU shorts in the first place. That "grounding" theory is bs.

 

Ill keep you all posted, thanks

*sigh*

 

How about this suggestion? Seems pretty logical to me

 

Ya but when i called the dealership, he said there was no relationship between the code and the injector/throttle body cleaning. I checked the codes before i brought the car in and there was nothing, and a code came up RIGHT after it was done, thing is, there's no way for me to prove that.

 

car needs an idle air volume learn, dealership can do it with a consult

Thats it, your idle is probably about 850-950rpm. spec should be 650-700 M/T and 700-750 A/T.

 

what does that cost?

 

As I've said before, if you're happy with way the car is driving and you have no light, you really have no worries. Don't drive yourself crazy. Drive the car for a month and see what happens.

 

There's no CEL, but the code is stored in the ECU even after it's reset. I guess im just meticulous when it comes to my car.

thanks for all your help!

 

One thing you might want to do though in case of future problems is to get Nissan to acknowledge that the code first appeared after they worked on your car.

 

I unplugged the battery a couple of nights ago (negative terminal) and the code has yet to pop up again. It's been 2 days now, no codes, so i'm really hoping that does the trick, actually, it's more like I'm praying!

 

I feel your pain!

 

Yours is a 00-01 model. You have an mechanical throttle body. You can relearn those but they are not so sensitive to throttle body cleans like the 02 and newer electrical TB. If you don't do a realern in those it will throw an ISC code not IACV. (idle air control volume valve/motor.
Now i hope they showed you a printout of the relearn completed like i told you to. IACV valve sits behind the throttle body plate that they actually cleaned and recomended to you initially. (they upsold it to you) So they did something wrong and they should fix it provided u went there right away.
Those IACV valves go bad sometimes in 00-01 max. It will eventually lead to stalling at idle in worst case scenario. BAD. So go back and complain to the manager and then tell them you will talk bad to Nissan Canada that they screwed up your car on an upsell. It's related and it should be fixed.
Also make sure you score them bad on a follow up CSI provided you receive one. Managers loose jobs over those.

 

oh what i always do before and after i do any work i scan the Engine and print that there are no codes(NO DTC). Ask them if that tech has any printout with before and after relearn procedure completion of NO DTC.
Also you can start raising your voice a bit but in a controlled manner.

 

I'm going to have to check the printout they gave me, but i checked it a little while back, and i really couldn't see anything in regards to the Idle Relearn procedure... now that i think about it, im pretty sure i didn't see anything in regards to my idle relearn... I guess that's it? i hope anyway

 

i would deff. wait a while to see if the light comes on than worry.

 

i reset the ECU last week (wed or thur) and since then i've done more than 600 miles and the code has NOT appeared again. I'm hoping it stays away for good. I think i still need an idle relearn as im reving a little high on the highway and when im in traffic.

 

You idle on the highway? I'm confused.

 

Yup, cause at times on the highway when i hit 75mph, im reving at 2600rpm and then after a bit of time driving on the highway, i'll go back down to 2450 rpms. I think that's a little wierd.

 

how can you calculate exact rpm?
Wind can influence RPM, also downhill while turning etc.
You measure idle RPM.