G3Nis

iTrader: (8)

How long did those chips take to come from Hong Kong, 2 weeks? I put my order in.

camaro

Changed the iacv,checked the ecm looks fine. (nothing looked fried or smoked).Idle speed is perfect, engine is running smooth. did the relearn.reset the throttle.Only problem is the engine at 1500-1900 rpm is erratic. What should I do next.
AT 1700 rpm I closed the inlet of the iacv in the throttle body.The engine was stable (not erratic).
What"s next please.
new member this is the only way I can get some info.
Thank-you

camaro

the hissing sound that is heard is coming from the throttle body. It is coming from the IACV inlet in the throttle body.I found it when I put a cardboard over it. This is when the rpm became stable. This is what I do not get.

MaxStress

This is not what I wanted to hear, I'm in the middle of this nightmare and I hope all goes well. This forum is very helpful, I just wish I would have read this thread before I bought mine.

Smooth_Operater

Yeah, I got this problem now but I plan on just unplugging motor mounts, replacing IACV and sending ECM to AutoECU.com. will let you know how it goes. They said after I get my ECM back I shouldn't have to go to the dealer for reprogramming so that's good

Smooth_Operater

Found a better site that repairs ECM's for $160 including priority mail shipping back to you. It's www.avproecm.com they are in Fort Walton Beach, Fl. Talked to the guy on the phone and he said it takes him about 6 hours to repair, comes with lifetime warranty and ships back to you the same day

05nissanmax

Ok my culprit is a 2001 Max 5-spd. I first had trouble with car dying when you came to a stop. It had the 505 IAC code so upon checking on the replacement part at a rate of around $200 I hit the junk yard. I bought complete throttle body assy. for $45. Replaced hole unit and had only an occasional high idle problem when you would come to stop, so called Nissan tech I knew and he said it would have to have the re-learn procedure performed. I took it in for this to be done and he said that the ecm would not accept the procedure and could possibly have bad ecm. I learnerd that i could turn off car and restart and high idle would go away for weeks or months at time. Never throwing any codes during this. So I just recently bought 2005 Max and sold the 2001 Max to a friend. 2 weeks later they call me and car is doing the eratic idle mentioned by others going from 1000 - 2000 rpm and had no codes, but had burnt smell coming from ecm area. I figure the ecm has finally given up so I find matching number used ecm for them and they ordered it $140. Ecm was installed today, and it immediately fried the replacement ecm. The car was still running on the original ecm just had the eratic idle. So after reading here I am gonna view the original ecm internals today and see if there is any burn outs, just can not understand why it immediately fried the replacement? Would IAC need replacing again?

Just to show that Nissan will not tell you about problems they have I have a print out from NAPA dealer on history of this problem for this model of car the report is from all across US at all NAPA dealers.
It shows 73 reports of repairs of IAC and or ECM between January 2009 and June of 2010.
It also states a Nissan TSB (NTB01-076B) for wiring harness problems under hood, near passenger strut tower.

05nissanmax

Anyone?

mccpu

I got P0505. I think my motor mounts took out ECU and IACV.
A week before, I heard the buzzing noise after shutting off my car but I didn't realize it was coming from my car.
At this point, my only option is to replace all three?

j_p_designs

Ok, I've been on here since I bought my max 2 months ago trying to figure out my idle issues. Good thing I still have my 00 frontier crew cab as a backup driver.

First, is IACV and ICV the same thing? Idle control valve? I just replaced that part on mine 2 days ago and I believe it is actually worse now. It dies at almost every stop.

Also, where are the motor mounts that I need to disconnect? Anything else I should do? I have cleaned the MAF and TB.

I don't know where the ECM is - can someone tell me?

blkAEmax82

iTrader: (16)

Did you do the idle relearn? Also the ecm is located inside the middle dash under the radio.

j_p_designs

No I have not done that yet. Thanks, I'll do the idle relearn and then if it doesn't help I'll check the ECM.

G354DorK

Can anyone tell me why my ECM is different internally from the ones shown?

I originally posted this on a different website with no further help:

Hello, I recently acquired a 2000 I30 with the infamous P0505, vehicle had a problem staying running on a cold start but after warm would idle at aprox. 950 rpms I checked resistance on IACV resistance turned out bad, replaced IACV w/ brand new one, did notice slight green corrosion build up on my plug that connects to IACV good sign of liquid leaking past the seal. Now with the new sensor vehicle has no problem staying running on a cold start, starts at 1200 rpm then as it warms creeps up to aprox. 1450 rpms on N or P, on drive it idles aprox. 1000 rpm, vehicle has hard downshifting from 3rd to 2nd & 2nd to 1st. I have cleared the P0505, code eventually comes back figured Ecm was toast, I opened the Ecm I did not notice any signs of damage to any of the chips/resistors, the person who sold it to me did say the Ecm was recently replaced with a used one & programmed to work. After the IACV was replaced I performed the Idle relearn w/ no success. Have tried a few times when (brown) connector comes off idle revs up when plugged back in in less than 5 secs idle sets at 1500 rpm.I used EC-67 on the FSM for the procedure.

Last night I checked for continuity on my Ecm main connector to the IACV, continuity does exists. I do have 12v to the Iacv on 2 of the terminals.

Can the Ecm still be bad and not show any signs ? Does not smell burnt. My ecm does not use the STA509A it has 2 STA508 with no signs of damage.

Smooth_Operater

Interesting, my car is doing the same thing. High idle and rough downshift (almost feels like the car is hiccuping when decelerating). I sent my ecu off 2 days ago even though I didn't see any problems like u. Once it gets back, my mechanic will install a new iacv and the "fixed" ecu and see how it goes

G354DorK

Let me know how it turns out, Thanks

KRRZ350

iTrader: (29)

Got a car with this issue right now, coolant fried the motor.

mccpu

so I ordered motor mounts and IACV from DaveB and found a used ECU on car-parts. I had my mechanic install them. Towed my car to the dealership to have my keys programmed.

I had three keys, 1 original Nissan key and 2 aftermarket keys which were all working before. After 30 minutes, Service advisor says the tech tried to program the keys but could only program Nissan key saying the aftermarket keys were being rejected. She offered to sell me new keys for 89 each. As soon as she said that, my instincts told me that she's trying to scam me into buying new keys. I told her that makes no sense to me. After arguing how that can't be possible, I just left with 1 working key. I am thinking I should go to another dealership to get them programmed again. What do you think?

mccpu

I have a 2000 Maxima and my ECU looks exactly like yours. I believe the other pictures were from 2001 Maxima ECU's. When I popped P0505 code, on that same trip, I noticed burning smell coming from the ECU area. When I opened up the ECU yesterday, it didn't show any obvious signs of damage...

ravis1019@gmail.com

Electric motor mounts can burn out ecm, disconnect both of them. Doesn't do nothing to car

G354DorK

Yeah thats odd, I dont see any damage with mine either. I found a used Ecu for $100 that looks in mint condition do you know if I would need to buy new keys to program or can my original keys be reprogrammed to the replacement ecu ?

EddieBob

I'm a newbee so I can start my own thread, but long story short - 2001 maxima was running fine, just stop while drive like the fuel pump went out. Hooked my scanner up to it and scanner cound not communicate. Noticed that the Check Engine light does not light up. Pull out the service manual and followed the steps for No Power to ECM. I've found that one of the 15A fuses is blown because the ECM relay is not getting power. When I put a new fuse in, with the ECM relay still disconnected, it blows the fuse right away. Manual says check joint connected 12 or open short between fuse box and ECM Relay. Anyone knows where the joint 12 connector is at or have dealt with this issue before? I also disconnected the motor mounts, IACV, TPS, Starter, and ECM computer but still blows the fuse.

dustey

iTrader: (1)

Any updates??

Smooth_Operater

Actually yeah, about to go pick up my car from the dealer today. Finally fixed! Anyway, here's what I did and what problem I had. First, my car didn't cut off at idle like most people on here said, mines just had a high idle (around 1100k) and when you decelerated the car would jerk when changing gears. The first thing I did was replace the IACV with one from Autozone for $230 after tax. That didn't fix my problems so I took out the ECM and inspected the STa5059 (I think that's it) chip and found out it was in great shape. Afterwards I sent the ECM to avproecm.com in florida and they changed the chip and sent it back to me via priority mail for $160. I took the new IACV back to autozone and got a new one (Free) just so I could know that both were installed at the same time. Still not fixed so, I just drove the damn car with a SES light on and the high idle for a month. After I got some extra money I took the car to the dealer this Monday and found out that after changing those parts I needed to have idle reprogrammed and they say its running fine. I tried the manual idle relearn that I found on here about 10 times with no luck. I guess the dealer can do this best. Hope this helps, I have a 01 i30

dustey

iTrader: (1)

So what was the original problem? Just the jerk when changing gears and high idle?

Smooth_Operater

Yes, and the SES light for P0505

Smooth_Operater

Any luck with your car dustey? What problems are you having?

dustey

iTrader: (1)

I've been chasing a misfire for the last year. P0306. Never any other cylinders, comes and goes without rhyme or reason. I have tried all of the usual (injectors, plugs, coils, etc). All OEM parts. I have a buddy that works at the local Nissan dealership that has double checked everything I have done plus a few other things. He has said it's the ECU.

I pulled the ECU and found some corrosion on the board (I made a post about this not too long ago).

I called and talked to the guy in MN that advertises (on eBay) that he fixes Maxima ECU's. He said what he does wouldnt fix the problem I had.

I finally sucked it up and bought a new (er, reman) ECU from the dealership (employee pricing, but still expensive). My buddy at the dealership is going to install it Saturday. All I gotta say is... it better fix it.

Smooth_Operater

If that don't fix it, I would look into getting a new car

sticky

i have been dealing with mine for 3 weeks now rebuilt ecm new iacv,new tps twice,unhooked motor mounts idles perfect but give it throttle and it surges up and downwill not go past 1800rpm

hungeeee

Anybody knows what this Chip is? I have the same problem as everyone else but my burnt chip is not the same one as everybody else. My car is a 2000 maxima gxe. Is this the chip that controls the motor mounts or the IAC?

Smooth_Operater

I'm not sure what chip that is. What number is on the chip. Try searching that and see what it controls.

CobraKing

Hi All, my wife's car stalled the other day and P0505 came on. I've already unplugged the engine mounts and I wanted to visually inspect the ECU.

For the love of me I couldn't figure out how to access the four screws holding the ECU in its bracket. There is no space at all to stick in any kind of screwdriver or ratchet if I view it via removing the panels on the left and right of the console (on the floor of the car, near the gas pedal and below the glovebox).

Can anyone advise of an alternate method to take out the ECU? The car is a left hand drive, 2000 Maxima GLE.

Thanks.

01BLKSE

Well another one here.. I have a 2001 Maxima SE / 5MT that was throwing the SES for a IACV. I replaced the IACV and it worked for about 1 hour, then it threw the code again. The ECM seems to be fried and I want to send it out for a rebuild then re-install.. What parts should I install before hooking up the ECM ? Should I just procure the parts and have the dealer install so that they can set the idle correctly ? I really don't want to burn anything else up ..

I was told that I would need to replace the IACV, TPS and Air Temp Sensor before installing the rebuilt ECM... ??? HELP PLEASE... !!

Smooth_Operater

01blkse
Here's what I did. I changed the iacv first and since the ecu was fried (which I didn't know at the time) the iacv messed up again. Since I bought my iacv from autozone I took it back and got another one for free. But, before I put the new iacv in, I took out the ecu and sent it to this guy at autoecu.com. you can go to his website and give him a call. He's very good. I want to say it was $160 for him to fix the fried chip and send it back to you priority mail with a one day turnaround. After I got it back I installed the ecu back in the car, changed the iacv and started the car (the benefit of getting your existing ecu repaired vs getting one from a junkyard is that you don't have to get your keys reprogrammed, think of it as plug-n-play). Idle was still high so I tried to relearn I found on this site but it didn't work. So I drove the car to the dealer and had them do a idle relarn using the computer and my car has been fine since. Its been about 5 months

Smooth_Operater

I took out my ecu by removing the plastic covers by the ecu (one is by the gas pedal and the other is on the passenger side under the glove box behind the radio). I then used a 8mm wrench(I think that's the size) and kinda layed on the floor and worked the screws out. Took me a while do to the lack of room but I got it. Hope this helps

Darkrock

This is a copy of an email I sent to NAKIS-you need to read his post carefully! Otherwise you will continue to fry IACVs and ECMs! The most critical step other than the obvious part replacement are the directions on page EC-111. YOU MUST HAVE THE TECH DO THIS PRIOR TO REKEYING AND STARTING THE ENGINE. Here it is.....To NAKIS:
Thank you!
I have a 4/2001 with continuous IACV valves replacement for years and a couple ECM's and my last "fix" with this issue was to close out the throttle with the idle screw and it worked for a couple years. Finally stumbled on your thread or odyssey with the ECM short and your thoughts about TSP and coolant problems in conjunction with the IACV. A week ago the Maxima fried the ECM and IACV. OBD codes 505 and 612 (dead ECM lots of carbon on the cover plate and at least 4 circuits burned through the 509 was melted) and another for the fuel regulator. I replaced the IACV, disconnected both EC motor mounts and bought a used matching ECM (EBAY which looked totally rebuilt on the inside) took it the dealer for rekeying with instructions.-----> top of the list requiring the TECH to follow instructions on EC-111 before reprogramming. Had a 21 year TECH on it and it took him an hour or less to close the throttle, rekey, and perform idle relearn. Good to go!
Thank you

Hats off to Nakis, et al

**Posted on the "coolant bypass thread"---->Just completed it today and I live in a fairly cold clime in N. IL and will report if any issues. But I view this as additional insurance against coolant contacting IACV. I have found corrosion at the pin base of at least 2 IACVs that have faulted and possibly a third to not closing TSP before starting.
Procedure: Purchased 5/16" brass split hose mender with the claw backs. Disconnected each hose from each side of the IACV/TB and joined each to the brass mender and clamped with existing. Capped each IACV port with 3/8" ID black chair tips and these aren't as snug as I would have liked but not certain I even need any but it looks more finished. Fired up with no issues. Maybe $3.00 with Cook County tax and might have saved me real money if done sooner. Ignorance isn't bliss! It's expensive!

allornothing

Question, after reading these posts, for a person not experiencing any issues and obviously not wanting to go thru what many have had to do, would you disconnect electronic engine mounts and replace IACV as maintenance measure? Or would you just inspect motor mounts and clean IACV as preventative maintenance?

Thanks

Infi30t

So bringing this back up, I am having an issue with my 2000 I30t right now. I replaced the MAF sensor and now it is stalling. My repair shop is relating it to the IACV and they say that nothing is burned up in the ECM so could replacing the IACV be the right choice before something burns up?

christopher.spitler

IMHO, unplug motor mounts now and make sure you check any SES codes that pop up. Also, monitor for a rough idle or stalling at idle, as those are signs of IACV failure.

Darkrock

Preventative Maintenance: COOLANT BYPASS.
OR
Car dies while driving $80.00 tow, 1 hour reading this thread (got lucky finding it), pull ECM- the 509 chip is melted and surrounding circuits fried replaced used $200.00 (match numbers) EBAY, check IACV and pin 6 is shorted (more like melted) $250.00 Auto Zone, check continuity for all pins all are in the low 20s (ohms), tow $80.00 to dealer for rekeying, TSP closing (FSM EC-111/EC-116), and idle relearn $210.00. This is an $820.00 journey that the coolant bypass (see post above) would have prevented. Not counting the multiple repairs of the same thing over the years. COOLANT BYPASS.