Nomad

iTrader: (5)

have you guys solved this problem? My engine acts the same way, revs up to 3k rpm. I don't know what could cause the problem. I guess my ecm fried

Andrei post if any updates?

michaelnyden

iTrader: (15)

I don't get it, so what's to stop it from frying another one if you stick it in there...

mine revs to 1300 or 1400...with the bored out TB...still haven't had access to a consult II to do the learning procedures...I am fed up with the do it yourself ones...lol I am convinced it won't learn if the idle is above 1K...and I can't seem to get it below that...

Nomad

iTrader: (5)

Have you had 0505 code before you 've changed your valve?

P. Samson

For the Idle Air Volume Learn "procedure" to work the engine has to be warmed up and the idle speed CORRECT. To have this happen you have to have the throttle plate "positioned" correctly in the TB bore at idle and therefore the throttle stop adjusted correctly, then the TPS is "adjusted", the closed position memory accomplished and then the Idle Air Volume Learn. The end result is that the IACV "pintle" is located somewhere within the limit of it's travel so that for ANY engine loads, or changes in engine loads at idle, the ECM can actually control the idle to the programmed idle speed by moving the IACV WITHOUT the IACV "bottoming out" (running out of travel) and the ECM knows where the IACV pintle is. If everthing is not done correctly or adjusted properly the IACV can run out of travel and then the problems start.

michaelnyden

iTrader: (15)

nomad, I did not have the code before...but I never changed my iacv...in fact, I left it plugged and just removed it from the TB, b4 I took out the TB and replaced with the bored out one...I removed the metal washer so I wouldn't loose it in the engine bay and then left the iacv gently resting on some wires down below...so I know that the iacv is good, never replaced and was working perfectly, hence I know it's a learning issue/tps or throttle plate adjustment issue...

Nomad

iTrader: (5)

sigh my car is back on track!!!! a took everything a part today and was trying to find what the problem is? I measured resistance of old IACV valve and the new one both had 22.+ @ home temp (74F). Then I took apart the new valve (solenoid) and was astonished that it was all the way back into the body ]->there was no way solenoid rod could touch IACV butterfly because my old one was like ]--->. I was sure that my old solenoid was fine cause I've never had any DTC codes. Long story short, I put old solenoid w/ new valve body and everything works now ))) Though i'll probably have to make a trip to stealership to make timing advance and idle air volume proc.
-------------------------------P.S.-------------------------------
Basically my problem with faulty IACV valve was caused by dirty air filter. Previous owner probably had never changed it. It had tons of dirt leaves and sand when I was replacing it.

michaelnyden

iTrader: (15)

didn't happen to take pics?

Nomad

iTrader: (5)

no sorry. i was totaly in solving problem. Though I can snap a pic of new solenoid [img=http://img442.imageshack.us/img442/1424/pictureaf7.jpg]

Nismo98

iTrader: (7)

Hello to everyone who participated in this long ongoing thread... My Maxima has been sitting in the garage for about a month now until last Friday when I finally had time to take it to a local dealership in order to get the Air Volume Relearn process done. I was hoping that everything would go pretty smooth, and I would out of there within an hour. Although this bastard in service department did want things to go that way. So here is how it went... After about 20 minutes into the process the guy @ the service desk tells me that things are not looking too good because the ECU doesn't want to accept the program from the Consult II. Another 5 minutes go by and the tech brings out my old TBP sensor and a print out. On the print out I see that codes for IACV & TPS came out. Also the spring inside the TPS lost it's tension which I've noticed before when I had it apart. So I ask the guy how much would it be for new TPS just to get an approximate idea on what to accept from him. He tells me that he doesn't have one in stock, but could have it this afternoon and it's going to be $141.00 As soon as he tells me that price, I call the Nissan dealership which is about 15 miles away from me, where my buddy has an account. The guy at parts department sold me numerous things in the past and tells me that cost price for TPS is $119.45 My price was a lot less so I tell myself that this guy is trying to f*ck me for sure, I gotta keep my eyes open. So now he can't do anything until I replace the TPS sensor. I tell him that I'll be back in 45 minutes with my OEM TPS. So approximately 2 hours since I initially brought my car in, I return and the tech installs a brand new TPS and continues to run the program. Still no luck, and now there are 3 mechanics and that old bastard are under the hood of my car trying to figure out on what's going on. Another 30 minutes go by and I see that panicking since I am getting more what I payed for. So the guy at service comes out and tells me that they were able do anything because the idle would not drop. I ask where is the idle at right now, service guy tells me 2500 RPMs. Also his conclusion was that the ECM is fried. He brought me the first print out which is going to be posted on the left. I ask to speak with a tech. As soon as he stepped out I ask him what's going on with the idle, his response was that he got it down to 1500 RPSs and it jumps between that and 1800 RPMs. I ask him for a correct print out of the readings and that's the one you'll see on the right. I still have the 0505 IACV code which has gone away even after he reseted the ECU, and it came right back up as he said. The entire service department and two of the mechanics came up to a conclusion that the circuitry for IACV in my ECU is fried. I finally finished my conversation with younger buy who ended up to be service manager. I was able to set up a deal for them to try this process again on them after I replace the IACV once again.

monty31

iTrader: (1)

Remember when I posted this on the first page???? This is becoming more of a common problem that most people on this board aren't up for considering. You'll have to get a used ECU from car-parts.com for around $160-200, and then go to the dealership to have them reprogram it for yout keys (or NATS will kick in). The dealer charged me $107 to reprogram the ECU and keys.

Oh and it's really important that you get the right ECU. Ie: Auto vs. manual, Traction control vs. No traction control.

Nismo98

iTrader: (7)

So after fighting with 0505 code for some time, you ended up replacing the ECU? Where you able to preform the air volume relearn procedure after the ECU replacement? Now I am more convinced that it could be the faulty ECU since you are the second person to tell me this. Mr. DaveB also recommended the same thing after talking to his mechanics @ his dealership. The thing that I still can't get, is that why the car would start and run just fine after giving it a little bit of gas in the beginning prior to my IACV replacement?

Andrei

monty31

iTrader: (1)

The idle relearn is included when they reprogram your new/used ECU. The $107 I spoke about included everything. If the service department rep is skeptical and gives you any **** then go somewhere else. No one I talked to believed me and eventually when I got the mechanic to do it the manager offered me a job lol.

My car also ran just fine with the CEL then I made the mistake of cleaning my MAF/IACV which raised my idle. Since the ECU was bad, I couldn't perform relearn. The worst part about this whole thing is that you can get EVERYTHING replaced free if your car is under 80k. I was just at 100k when all this hapened so I was SOL.

Nismo98

iTrader: (7)

Where is that thread which you've started in the past, could you please post a link? I just can't believe that the circuitry of the ECU would fry just like that.

Andrei

monty31

iTrader: (1)

I never made a post after I finally fixed it but here are a few posts related to the issue that may be informative for you.

http://forums.maxima.org/showthread....highlight=iacv
http://forums.maxima.org/showthread....highlight=iacv
http://forums.maxima.org/showthread....highlight=iacv
http://forums.maxima.org/showthread....highlight=iacv
http://forums.maxima.org/showthread....highlight=iacv

Again, I searched on carparts and was able to find a auto/non traction control ECU for $160 within 25 miles. There's really no way to get around the Nissan high prices unless you can bribe someone with access to a Consult terminal.

Nismo98

iTrader: (7)

From what I understood after talking to DaveB, the tech with a Consult II would be able to detect either or not the ECU is actually receiving the readings from the IACV. For some reason, I am 90% sure that I have a defective IACV.

Andrei

P. Samson

Nismo......did you resolve the apparent throttle idle stop issue? If it isn't adjusted "in the ballpark", you'll just create problems again after spending more money replacing components. This is what gives you the correct Consult ll "Idle Air Control steps or counts" after the Idle Air Volume Learning procedure. If the Idle Air Control steps are not correct then the throttle idle stop is readjusted to bring the "steps" into specs. (2 -10), and as I've mentioned before this ensures that the IACV doesn't run out of travel.

monty31

iTrader: (1)

Have you tried ohm testing the IACV, and or listened to make sure you can hear it functioning?

PAREDLINE

why dont you try putting the old parts back on. maybe you got bad new parts

Nismo98

iTrader: (7)

I asked the tech to take a look at the throttle stop bracket to make sure it was in the right position, and going by his words it was set correctly. Like I mentioned earlier, as soon as I start the car I am seeing 1500 RPMs. Once the car begins to warm up, the RPMs start to just from 1500 to 1800 and so on. I might try the Air Volume Relearn process once again without the Consult ll.


I didn't measure the ohms on the IACV, and the said part is that I don't hear it humming once the ignition gets turned on.


I wish I had it... I always place the old part which I replace back in the box until I make sure the new one works properly. I still can't forgive myself because I disposed it after the install.

Andrei

P. Samson

The dealer using Consult ll can physically operate the IACV IF the ECM, the IACV and the circuit are serviceable obviously. The dealer should also have been able to determine for sure if the IACV was good or not and it appears that he may have done that and then deduced that it is an ECM problem. Nismo.....did the dealer say that the IACV was definitely the problem, or that the ECM was the problem? Out of interest, what does the throttle stop adjusting screw look like now? You cannot do/it is useless to do the Idle Air Volume Learn unless the idle IS correct.

Nismo98

iTrader: (7)

The only reason I went to this dealership is because it's a minute away from me. I didn't want to drive my car with 3000 RPM idle to the dealership which I trust because it's half an hour away, although now I think that I should have. Dealer conclusion to this matter was the fried ECM. Right now the screw is 7 threads out. Correct me if I am wrong, but that's where it should be as you mention a while ago. Nobody at the dealership mentioned anything about a faulty IACV, only that the ECM is fried. I guess I can understand why I am still getting 0505 if the circuitry in the ECM is fried. Tomorrow I am planning on taking the car to the dealership where I purchased some of my parts and my other car. Hopefully I can get a tech to perform the procedure once again and see what he has to say. It's killing me to see this every time I step to garage to have a smoke.



Andrei

P. Samson

Good, if there are about 7 threads of the throttle stop screw exposed "behind" the lock nut then it sounds like the dealer has adjusted the throttle idle stop, and along with the new TPS, properly adjusted, this is a good starting point. Probably reflected in the 1500 rpm "only" idle.

Nismo98

iTrader: (7)

To be honest with you, I was the one who adjusted the position of the screw after your recommendation. So my assumption is that the throttle idle stop & TPS are set. I am waiting on a new IACV and searching for ECM as well. I really would like to be done with this mess.

Andrei

P. Samson

When this gets "wrapped up" at a dealer, ask for a final Consult ll printout of the warmed up idle readings including the Idle Air Volume "steps". It should be within the 2 - 10 limit. This will be the "proof of the pudding".

Nismo98

iTrader: (7)

I found the ECM nearby in case the replacement of the IACV doesn't help. I am not too sure which idle air volume readings you are interested in, please specify so I know what to ask for.

Andrei

Nomad

iTrader: (5)

Andrei not to hi jack you thread.

After my last post about solved problem I went to dealership to get idle learn procedure. (My friend works at there.) Well after two hours of trying he confirmed that my ECM is more likely burned. It continued to throw P0505.
My friend also told me that he recently had 3-5 cars with the same problem.
I'm currently trying to find ECM w/ traction control.

Nomad

iTrader: (5)

Monty Can you explain me how exactly you replaced ECU.

I mean as soon as you swap new (used ECU) Nats kicks in and car won't start. Did you replace ECU yourself and towed car to dealer or dealer did it for you?
Thanks just trying to find a best way to do swap.

Nismo98

iTrader: (7)

No problem what's so ever, everyone is more then welcome to step in & try to figure out what's the whole idea behind this IACV>ECU>$$$ deal. What symptoms did you car have after the air volume relearn procedure did go through. Also any idea about the other cars which you've mentioned. I have a feeling I'll be ordering the ECU tomorrow.


That's a very good question, I was trying to figure out the best option in a situation like that. Since the ECU is plug and play and your are able to drive the car to the dealer, it can always be done right on the dealership's parking lot. Towing is an option, but it'll have to be pushed in into the shop anyway.

Andrei

Nomad

iTrader: (5)

You know how guys at the dealership work GOTTA change it? now problem pay for new part. I've just heard that on some cars they had to replace whole TB.
As for Idle learn my friend just told me that ECM kept throwing P0505 and won't re-learn. Though I didn't have any codes related to TPS and stuff. Right now my car idles @ 750+ when on D and 1100 when on P or N. Noone can tell what causes ECM failure, HUGE BUG that NISSAN has to fix for free
BTW anyone knows how nissan releases TSB's is it based on high volume of same problem among specific model?

Lets wait for monty's reply.
Called my friend for replacement and reprogram quote: $200+

P.S. I'll deff take pics of burned ECM as soon as I do Swap.

project240

Here are some pics of the IACV motor siezure char broiling the ECU

Changed IACV now need new/used ECU.

2001 Max GLE w/traction





How did I get here? Well to make a long story long,
a. erratic idle, swing from 1.5-2.5k
b. hook up scanner get P0505
c. hunt for used IACV from wreckers
d. bite the bullet and get new IACV from dealer
e. decide to shortcut and just swap IACV motor from new IACV
f. e didn't seem to work, now replace entire ivac
g. regret e
h. get frustrated, consult forum
I. Attempt Air Volume Learning 84 times
J. Take to dealer, pay diagnostic charges
K. Learn that the ECU is fried and $785 CAD plus this plus that
L. remove ECU at home
M. Take photos
N. Whine on forum.

monty31

iTrader: (1)

I drove my car to the dealer (on the blown ECU) and plugged my new ECU in when I got there so that they couldn't charge me a bunch of money to just plug in the new one. I think Nissan would have charged $50 just to plug in my new ECU. They had me drive my car straight into the shop when I got there so I don't know if you'll have that option. If you don't drive it into the shop, just tell them to plug in your new ECU without actually installing it in the brackets so that they won't charge you for a "install". The whole reprogramming procedure should be under $150 if you explain what you want them to do in full detail before you leave the car with them. I told the mechanic to call me if it was going to exceed $150. Hope that helps.

Love_00_Max

Why should the ECU get fried up -- shouldn't there be some fuse in the path or circuitry in the ECU to prevent this? I think if the board was designed well and engineers thought about this scenario, this wouldn't have happened. This is frightening the least to say!!!

project240

I know, this situation would have been eaisly solved with a two bit fuse. Every manufacturer has their design problems but this is really poor. Even I could have forseen this if I was on the engineering team.

Can anyone verify if these parts are interchanable?

3U A56-Q80 ZA1 0X25
with
3U A56-Q80 ZA1 1109

I was told that the ecu has to match exactly or it will not work. Is this correct?

2001 Max AT w/trac
VIN: JN1CA31A01T10****
23710-5y011 (ECU)
23710-5y010 (ECU)

monty31

iTrader: (1)

Just make sure it's the same year, AT, w/ traction control and they should be able to work with it using consultII.

Appears that the traction control units are a bit more expensive
http://car-part.com/cgi-bin/search.cgi

Edit: That link doesn't work but go through car-part.com and there's many available.

Nismo98

iTrader: (7)

Now thinking back, is it possible that my IACV was good to begin with? Or does the IACV fries the ECU once it goes bad?

Andrei

michaelnyden

iTrader: (15)

....what is even more worrying is that I still have my original IACV that has been working since day one...I left it plugged in...only unscrewed it via the two screws from the bottom of the throttle body (a put aside the metal gasket so as to not lose it), and I carefully let it rest on some wires down below while I changed to my new bored out throttle body and I now have p0505 and the idle is around 1200 and 1500 at all times depending on if it's cold or hot...crazyness! how can a known to be perfectly working iacv blow an ecu when it wasn't even unplugged and never changed out after sitting outside of my original TB with the harness still attached and the car off for only 30min?

project240

If I understand correctly I think where you're confused is that the IACV is 2 parts, one is the motor and the other is the aluminum body. I strongly suspect that the body leaks coolant into the motor and shorts the motor. The motor short then fries the ECU. The only preventive measure I can think if is to inline fuse the motor. I believe the fried ECU was over time and not instantaneous. I conclude this because I had intermittent problems with the idle some time ago and the motor must have been "dying" and stressing the IC that is fried in the above photos I took. When the motor finally seized/shorted the ECU gave up. If you have your motor out you can test if it is working by giving +12v to the center pin closest (there are six pins) to the tab to release the harness and ground to the pin on either side. I hope I have understood you correctly and this helps.

I suspect that the motor only dies if your IACV is leaking. IMO this problem is a serious design flaw and there should be a recall on this.

ABC

It's time for me to chime in here since I am experiencing the same problem.

Car - 2k1 AE Manual
car history: bought in Phoenix (it's home since new) 5/06. I doubt it has ever seen cold weather. Drive it home to Austin. Notice that gas mileage is lower than my '98 (which was perfect btw).
2 months ago - Take to RR Nissan for a diagnostic (about MPG)...$96 later they tell me the fuel mixture is bad and I should replace the MAF. I mention that I have heard (and demonstrate for them!) whines like air/vacuum leaks but they dismiss my claim becuase they can't hear it.
4 weeks ago - Buy a MAF, have a friend replace for $20 and get the ecm flashed by RR nissan for another $90 or so. Gas mileage unchanged. Thanks RR Nissan! $300 in so far!
1 Week ago: Ice Blast 07! Driving back from grocery car stalls while slowing down for traffic light. Starts fine, have to give a little throttle to keep the engine from dying until I get home. Once I get home my idle is surging back and forth from 1500-1800 rmp or so.
4 days ago: Pull code at Autozone: P0505 - IACV.
-Research on the 'org' all night and find various threads with no one saying how they were fixed, and a few that said the IACV+ECM did not fix them!
3 days ago: Driving into work hear 2 pops through the speakers in my car and smell ozone. -no fire under hood! Car continues to drive exactly the same.
2 days ago: take to RR Nissan and tell them that they will tell me that the ECM and IACV need to be replaced, and I mention that some people tried the same thing and were not fixed! Also tell them about pop/smoke and other idle symptoms.
1 day ago: RR Nissan charge me $195 to tell me they need to replace ECM and IACV and it will cost $1450 to fix. Me->Mad! Nissan trying to weasel out of FEDERAL LAW providing warranty on the ECM by saying it was ruined by the IACV. Made sure to get -in writing' the reason they denied a warranty claim on the ECM.

Fact: They put in another IACV (working) and this one also created a "bad smell" -their words- and wasn't working properly, obviously getting killed by the ECM just like...uh, the original one!

Dealer claim: 1st IACV failed and then killed ECU. Now the failed ECU makes the IACV fail in the exact same way??. Anyone up for logic?

Logic: If the 1st IACV failed -THEN- killed the ECU, how could a second working IACV have the same problem the 1st had? What makes sense to me is that the ECU failed and now sends bad signals to the IACV and causes it to fail just like it did to the 2nd one they put in.

Me: Not happy with them trying to weasel out of their legal responsibility. While I won't say every dealer is shady, this one has been underwhelming in every dealing with them!

Plan: To talk to Nissan corporate to get their "opinion" on this matter regarding the REQUIRED BY FEDRAL LAW warranty.

Fix: Get used ecm (~$165 shipped), New IACV (~$225 shipped) and put them in, tow to dealer, then have them (quoted around $45) program the ecm to work with my keys.

I truly believe that the kid that flashed my ECM damaged it, since it took him 2 1/2 hours! And said it was the first one he had done! After seeing posts of people whose ECM's were damaged by the dealer I believe you can add on another victim. Now I'm paying for his incompetence!

9DTALON

iTrader: (1)

I work in parts at a large volume Nissan dealer. We see this problem about twice a month. Here's a perfect example of someone trying really hard to fix something themselves and being without their car for waaaaay to long. Your original IACV valve went bad and fried the circuit in the ECM. Hopefully your new IACV hasn't been harmed from the bad circuit (I haven't seen that happen yet). If money allows, take your car to a dealer you trust, like, whatever. Purchase a new (or used) ECM, install it or have them install it. Have them do the initial programing on ECU, idle learn, NATS, etc... Pay the money, beg for a discount and get your car back. It's a small price to pay, i'm sure your time is more valuable than all of this. Call me if you need a good price on a new ECM. 614-771-2370 ask for AJ. (please have your VIN #)

Love_00_Max

If Nissan were to own up for this, they should do so for Faulty Ignition Coils and Poor Braking system. Did you see what happened for the class action lawsuit on Toyota for their sludge problem. The Japanese are getting away with these becoz far more cr*py vehicles is on the roads put together by Ford, GM and Chrysler. These are small problems, live with it and don't mess around with the IAVCs. Note sure how it can be cleaned if so much fear has been generated by some cleaning it... Some of 4th Gen IAVCs are pretty dirty.