Stru

2001 Nissan Maxima SE

Yes, I know about the P0505 and the IAC and the frying of the ECU but I don't know if my issue is the same as everybody else's. Everyone else who has this problem seems to have idle issues (low idle, high idle, rough idle) or their car will not start AT ALL. My vehicle has NO issues at all other than the fact that it will not start when the engine is cold. I replaced the IAC, cleaned the MAF, scrubbed the throttle body, etc.


Here's a video I took for proof. Engine warm = starts just fine. Engine cold = must hold the gas steady for 5 seconds to start. Idle is normal, ride is smooth as a baby's bottom. Is it the ECU? Is it the IAC valve? I don't think it is because I have NO issues with the car other than the startup.

Trying to do everything I can on my own to avoid dealership costs. They want $150 just for diagnosis.

Skorp1on

might want to get yourself a copy of the FSM and try to go through some diagnostics that you have not done before. For example, you might want to do the Idle Air Volume Relearn procedure, check voltages at the MAF, check the TPS, etc.

I have 5.5 gen that went through (and still happening a bit) something and somewhat similar to yours which caused me having to replace the MAF sensor (due to DTC). Granted in my case, the car would go into Fail-Safe mode which doesn't have any power and would begin to "jerk" when i rev my motor pass 2k RPM. After I replaced with a re-man MAF sensor, the MAF DTC was gone, I got out of Safe-Mode, got power back, and was able to rev pass 2K RPM. However, the car was still experiencing a "Car will not start without depressing the gas pedal when warm problem". After reading through my FSM about how to do the Idle Air Volume Learning procedure WITHOUT CONSULT-II, the problems seems to have died down even though I may not have followed to the "T" all the steps/timing outlined.

G/L and hope that it's not the ECU that's the culprit...

Aviation005

maybe its fuel related? the temperature can make the difference. I think this cause holding down your pedal before starting disables the injectors, this may change the pressure, and make it spike so it starts. this is my best guess and seems most plausible

cjandura

iTrader: (3)

wow!

cjandura

iTrader: (3)

and BTW he's got a 2001 Arselink Aviation

cjandura

iTrader: (3)

im voting on a gasket leak or bad iac.

Rochester

iTrader: (3)

CJ, it's good that you offered the OP advice here, instead of just commenting on that other post. This isn't one of Aviation005's threads... every single one of which has been locked by a moderator. Just putting that out there for the OP, in case he wants to weigh the value of free advice by considering the source.

L_U_D_I_AMaxima

iTrader: (3)

if you had the P0505 code most likely the idle control valve is toasted... did you do the idle relearn procedure? It depends on how long the car was running with the bad IAC but the chip in the ECU could be fried as well... It does make sense for the car to act differently when cold and warm due to the vale being connected the cooling system...
I would start with the idle relearn procedure and see where that takes me... Also find the manual and check the voltage at the MAF... Another try will be the actual crank position sensor...

dared3vil0

Hey man, Can you make a DIY thread on how to remove the valve covers and show me it running? I'm really interested in it and would love to see it work before i do it! Also, I just did your dryer vent air box mod and i think i got about 23.98 more hp and 11.76 Ft/lbs more. Thanks bro! Your mods are really a refreshing change to all the stuff! Your like, My idol!!!!1111!!!

T_Behr904

2damax

I don't want to cause this thread to go way off topic but can the mods please ban Aviation. It is bad enough to create dumb threads but it is hurting the quality of the forum to watch him ruin well-intentioned discussions.

dared3vil0

Sorry, I'll stop responding to his posts. Just so much fun.

Fakie J Farkerton

iTrader: (51)

I would kinda miss him.
It's not just me.
It is sad he offers advice, but I hope he keeps posting questions and showing us what he has done to his car. Great stuff sometimes.

cjandura

iTrader: (3)

You Lie! And you just want to see him clown car his maxima!

Aviation005

litch

iTrader: (2)

2damax

Mods are slackin here.

Stru

Lol the posts made me giggle, thanks for the help everyone.

Unfortunately I really don't think that anyone could diagnose the issue properly without testing everything as Skorpion said. I'm not all that great with cars yet so I'm bringing it to the dealership and going to have it properly diagnosed on Monday. I'll give you guys an update and then maybe we could talk about some repair support lol thanks a lot.

Oh and what's with the hate on Aviation? I don't browse this forum enough to know him personally, but he seems like an okay guy just putting in his two cents for support. I give him credit for atleast contributing, unlike the other 300+ viewers.

2damax

First, do NOT go to the dealership. Go to an independent mechanic you can trust.

Second, you can search for aviation's threads and see that he, as someone so cleverly stated, is the little kid at the adults table.

koreanthunda

If you have the p0505 code then check for a burnt electrical smell around the fire wall and center console near the gas pedal . The. If so remove your computer and check for a burnt sta chip .
The u need to replace he iac valve I went on e bay and found the valve for $118 and the repair job in California at module repair for $94 then u need to complete the relearn procedure yourself and there you go. If its at the dealer be prepared to spend $2000 about the price of the car . DO IT YOUR SELF the dealer is going to tell you to get another computer and the. You have to reprogram all of your keys too .

Stru

Okay SO I brought it to the dealership (before 2damax told me not to) and they told me everything that is wrong with the car. The ECM is apparently toast, but I'm gonna remove it myself and see what I could do before I go ahead and drop 2 grand. Anyway here is a screenshot of the repair estimates.



I'm not a mechanic or anything, but I can change spark plugs my damn self. Not exactly sure about the coils though, but I'm not worried about those right now. O2 sensors and cat bull**** I will fix with a different mechanic some other time UNLESS they will short out the ECM as the IACV did.

Basically I need to know what I should fix right away when replacing the ECM so nothing else gets shorted and roasted again. I know the IACV and all that crap needs to be changed along with the ECM, but how about the ignition coils and O2 sensors and ****? Will that affect the ECM too?

cjandura

iTrader: (3)

Contact user Aackshun for a replacement ecu he works for a nissan recyclier.

2damax

I doubt the plugs and coils will effect ECM. If you can do the plugs then you can do the coils at the same time. The precat job is straight forward but you may want a mechanic to do it because that **** will be rusted up bad I bet.

Rochester

iTrader: (3)

New OEM Coil-packs are $85 to $100/each. Why would they want $1132 for coil packs and plugs? These must be some seriously magical spark plugs. For that matter... nearly $2K for ONE precat and a couple of O2 sensors?

I wouldn't have believed it if the OP didn't scan and post that estimate.

"Why George Bailey, you're worth more dead than alive!"

DjHackStyle

I cant believe those prices holy crap, is this dealer located in beverly hills or some other rich *** area? I dont think they want to fix your car cause they are exagerrating with those prices so you can just walk away. Anywayz heres some advice

Gut out the front cat and if both ur o2 sensors are bad i guess buy them and replace, install an o2 extender on the after-cat o2 sensor to eliminate that code.

Buy all 6 plugs and coils from the dealer and install them urself, the coil pack is removed to access the plug so if you can get to them (hardest part) then u can replace them

The ECM should be rebuilt i read a thread some where it was pretty cheap something like under ~$150 and u should buy a new IACV from the dealer aswell and throw it on urself after the ECU has been fixed and before connecting all this disconnect ur electric motor mounts or replace them with manual ones

Stru

I'm not worried about anything other than the ECM/IACV at the moment lol 1200 for spark plugs my ***. I checked them yesterday and they were fine, just the dealership trying to get more outta my wallet. I'm going to replace the MAF myself on it once the weather warms up. And just because I don't trust the dealership, I'm going to remove the ECM myself after I try all the other small fixes and examine it. If it's shot, I'll look into trustworthy repairmen (if you guys could recommend any that I could ship it to in the United States). Then I will purchase a new IACV and replace them simulatneously.

The only thing I'm worried about is all the connections and wires connecting the IACV to the ECM. From what they told me, everything in there was shorted from a coolant leak. Wouldn't these wires just fry the new parts as well? Should I have the dealership just do it because they say they'll replace everything. And I don't know of any mechanics in my area that I would trust rebuilding an entire IAC system on a Nissan. Tbh I think this is a job only for people who specialize in Nissan/Inifinitis. I feel like I'm risking a lot just changing the IACV myself.

Stru

OH and I'd also like to know if the bad cat or O2 sensors will fry the ECM too? Probably a stupid question but I know how godamn sensitive those ECMs are. I'm scared to even get a damn oil change.

kr0nik

Thanks for this video Stru. I just bought a 2000 gxe 2 weeks ago and have Exactly the same problem as shown in your vid. My gxe has 151k miles. Firstly wanted to let you know that your not the only person with this issue, and secondly wondered if you have solved the problem?

Kmbarreiros

I know this is an old thread but I too have the same problem:


Sorry for the sideways video.
The way the OP describes his problem is exactly how mine is other then no CEL on my car.
Any help would be greatly appreciated.

Pilm

The OP's idle issue was only at startup, once warm the idle was fine. Is your idle also ok once warm?

Kmbarreiros

Yes the problem is only at startup.

Idles just fine right after I help it along to get started.

Little background:
Purchased car in Dec of 2013 and didn't start driving it until July of 2013.
Every since I got this car it has had this problem. It also had the P0505 high idle which was fixed with a new IAC. Did not change computer since the IC's were fine.

Pilm

Sounds like the IACV is not broken if it eventually holds a steady idle, so I wonder if there is a problem with the ECM trying to set too low of a value at start up. The FSM says:

"the target engine speed ... optimum value stored in the ECM is determined by taking into consideration various engine conditions, SUCH AS DURING WARM UP, deceleration, and engine load (air conditioner, power steering and cooling fan operation)"

Notice the part about warm up. I'm guessing the target engine speed changes after the car is warmed up, so maybe the ECM is trying to program too low of a target speed at warm up and it dies, but after it gets warmed up the ECM shoots for a higher target speed the engine can maintain. If so I'm not sure how you can reset the warm up target, maybe an idle relearn will help, though the relearn is done after the car is warmed up so not sure.

D Realist

I was about to start a thread on this topic, but I figured it may be better just to post on this thread. I have had the same issue as the video with my 2000 GLE and my mechanic replaced the IACV, but he said that the ECM is fried. How much does it usually cost for the part and how much should it cost to be repaired? I am worried that I will replace the ECM and the car will still not run properly. The mechanic said it will be about $1700 to install a new ECM and that would also include the parts and labor for the IACV that he already replaced. He said that another option is to use an ECM from a fourth gen and it would be a lot cheaper, but it would still need to be revved to start until the engine is warm. I am debating if I should just cut my losses and buy a 5.5 gen. I can't believe the car is having issues because it only has 97,000 miles on it and once it is warm it runs smooth.

Ross.Overstreet

I'm in the exact same boat. 2001 Maxima SE with 130K miles. It takes a little revving to start, but once started it runs great. It also starts fine once warm. P0505 & P0100 codes. After the wife noticed a burning smell, I pulled the ECU to find the typical STA509A chip burned up. Dealer estimated $2200 to fix. It's an experiment, but I'm going to swap out the chip myself and replace the IACV and TPS. The chip is available for $10-15 on eBay and the IACV and TPS can be had for $140 total through eBay. The prices are so low that it's crazy. I know it's probably not as good as the OEM parts from a dealer but it's just an experiment on my part. I'm not going to put $2200 in a car worth about $2K. My max is old but I still love her!

From other research:
- The STA509A burns up due to a short in either the IACV windings or electric motor mounts.
- You must replace the IACV
- You should disconnect the connectors going to the motor mounts
- The ECU rebuild shops also say to replace TPS, not sure of the logic on this one but it's easy enough to do


Cheers,
Ross-O

Pilm

I would definitely try replacing the MOSFET in the ECM, it'll only cost you $15, so if it don't fix the problem then you aren't out much. A new ECM from Nissan will cost you $700-800, or you can send it to one of those ECM repair places and they'll charge around $150, but their repairs sometimes don't work, so there's a chance you'll waste $150 trying.

D Realist

Thanks for the response. I forgot all about that, my mechanic mailed my ECM somewhere and they mailed it back and said that it wouldn't work. I assume that is the same place that you are referring to. What is the MOSFET? I don't know if he tried that or not. I don't usually work on my own vehicle, but if it isn't to hard then I may try it.

Pilm

Take off the cover and look for the part STA509A shown in this post's photo:

http://forums.maxima.org/6957652-post27.html

If it's bad it'll usually show some sign of damage, maybe a chip out, swelling, black residue, etc. Take a picture of yours and post it, if the damage is only to the chip then it's an easy fix. Sometimes traces near the part also get blown, in which case you need to add jumper wires, however when mine blew traces were fine and I just put in a new chip and voila, it worked.

Ross.Overstreet

Hi Guys,

I called a bunch of different salvage yards today asking about ECMs for my 2001 Maxima. For the ones that had it, I sent over a picture of the burned STA509A chip in my unit and asked them to check theirs for similar damage. 3 different yards reported their ECMs had the EXACT same damage.

This scared me away from salvage units so I drove it up to Module Repair Pro in Van Nuys, CA. They looked at it and said they could fix it. Based on another one that they showed me, they add jumpers to replace the burned traces. I had considered doing this myself but it was just a little beyond my ability without a schematic (hadn't seen Nakis's info in the link above at this point). Without an undamaged unit or schematic to go by, it was hard to tell if any of the smaller traces had been damaged by the heat or not. The repair was $300 and Module Repair Pro said they could ship out tomorrow. Although 3 traces were basically melted away, they felt confident that they could fix it.

One other tip - Module Repair Pro recommended a HITACHI replacement IACV. I got a cheaper one off eBay and now I'm worried that it might short out and put me back in the same boat. Now I'm considering ordering a Hitachi and swapping it out again. Anyone had luck with cheap IACV by AIP Electronics?

Here's an example of what a burned IACV driver chip looks like.




Cheers,
Ross

Ross.Overstreet

Pilm - That's a great thread by Nakis! I wish I would have found it earlier. I could have given the repair a shot with that info. Guess I need to spend more time on searches!

Thanks,
Ross

koreanthunda

Don't get the cheaper iac valve get the hitachi suppose let they are made better and the new computer having a second safety feature to avoid this is a load of crap I just got my 2001 back from the stealership and it's back two weeks later it fried the new nissan factory computer . Previously I got the computer repaired to reduce the re programming costs of the key . $1000 to get to the point they should of replaced the iac valve also but never did I brought it in there because of a high idle they said there are two loops I. The fried circuit a high and a low . I ended up looking around while debating this debacle I fell in love with the 11 pre certified maxima sv . And have brought it back since the Bose subwoofer is blown in the passenger door and the rear bumper had marks on it from where the help was restarted and practically backed over a bush and left it there for three months until I stumbled upon her . I got a rental an 2013 Altima s for free . It should be back tomorrow . Let me tell you the Altima is a piece of garbage besides floating In the lanes and a slow 4 cylinder I am going to miss my maxima for one day . At least I am on vacation .