Progress

iTrader: (26)

Car is from Canada. I hope to God that is the only material difference.

Progress

iTrader: (26)

Now I'm losing my mind. I took the ECM out and visually there appears to be nothing wrong with it. I was expecting to see a fried chip but it looks cleaner than anything on the entire car. I am at a loss right now.

Does anyone know what else would cause a "no signal to coils"? Would a bad IACV cause this? I doubt it. Wiring harness?

Each pin on every chip, including the STA508A, is connected.

Here are pictures of the ECM:

unrealii

iTrader: (8)

What code are you getting? I had my dealer replace my IACV as a preventative measure while I had them do the my spark plugs. They also did an idle air relearn.

A few days later I got a P0505. I took it back to them and they did an idle air relearn again and so far no check engine light.

Progress

iTrader: (26)

P0505 is the only code thrown. Consult II didn't find anything other than that and "no signal to coils".

I'm thinking that if the ECM is okay (which it visually appears to be) then some other sensor (maybe Camshaft Position Sensor) is blown and not sending a signal to the ECM. Without signals to the ECM, it can't send signals out. Right?

Has anyone had this code and the car not start as their only symptoms?

I've ordered an IACV and will have it put in with the original ECM and see what happens. I can't think of anything else to do...

Swiyzee

I have a 2k1 AE 5MT, I had that happen too. I haven't replaced iacv yet. if the revs stopped bouncing and I have to press the pedal on cold starts to keep it goin, do you think my ECM is fried?

Progress

iTrader: (26)

Bump. Does anyone know if an ECM can go bad but look fine on the inside?

Progress

iTrader: (26)

Okay, tried installing the IACV with the existing (visually fine) ECM and no start.

What are my options other than parting out? Do I try ordering a used ECM and have it reprogrammed?

ColdRain

I'd atleast check crankshaft position sensor for any chipping or anything.

unrealii

iTrader: (8)

When you try to start, is it turning?

I'd go through the list on the service manual to check off the items one by one if it is not starting. Send me a PM if you need it.

Progress

iTrader: (26)

I'll try this. But wouldn't the dealer have done this if they concluded it was the ECM?

Progress

iTrader: (26)

It turns but doesn't fire. Last I checked the security light is not lit (so assuming it's not the immobilizer).

I'll give the FSM a shot.

bumbum6868

What was your fix I have the same problem.

TunerMaxima3000

iTrader: (4)

Thanks for bringing this back, I've had the 0505 code since I bought the car, I clear it and sometimes it stays off for weeks, then pops back on. Sometimes I clear it and it comes back immediately.

Is there any point in cleanig the IACV? I will start to shop around for pricing on a new one I suppose, and just replace it, but my mileage is quite low (around 60k).

Also, I hear about this 'idle relearn', but I thought this was only a procedure for the 5.5's that had Fly by wire TBs? Perhaps I'm wrong on that?

-Matt

nelledge

iTrader: (6)

Vehicles with very low mileage tend to have more problems with carbon, actually. Statistically, these cars are driven very short distances which do not allow the engine to reach optimum efficiency. Frequent cycles of low efficiency lead to an increased carbon build-up. The EGR system gets really bad. Just a side note.

To answer your question, I would just clean it.

CobraKing

Our 5th gen cars are almost a decade old - I would expect some electrical components and/or sensors to fail. On my wife's 2000 Maxima the IACV failed with P0505 and thankfully it didn't take the ECM with it. I got an IACV motor (non-OEM) of eBay for around $120 and replaced it myself - there is a fantastic how-to at the link below. Disconnect both battery terminals, and give yourself a few hours as you're dealing with old screws and bolts. You can use RTV gasket maker to create your own gasket in case you can't get an OEM one.

http://www.freeengineinfo.com/idle-a...eplacement.htm

I haven't done the idle relearn on my wife's car and it's driving OK - idle is at 750 and DRIVE with foot of the gas stays at 500. Dealer charges $120 for this procedure and I'm contemplating whether it's worth spending the money.

bumbum6868

Guys I am stuck. Has anyone in Houston been able to get the idle relearn procedure done and where did they have it done and how much it cost?

TunerMaxima3000

iTrader: (4)

Seems that is a dead link, at least it's not wrking for me.


Anyone have a DIY or link for cleaning it? I am overwhelmed with searching and haven't found one. I have about 20 tabs open doing research though, and mycomputer seems like it's going to crash anyday now.

nelledge

iTrader: (6)

Because I know how frustrating it can be to not have a working link, I've got a cache link for the one you referenced. Try this.

TunerMaxima3000

iTrader: (4)

Thanks so much nelledge, as always, your contributions are much appreciated. I will try to get at that ASAP, need to call the local Nissan on pricing for a new one also.

I would assume TB cleaner is fine to use on any carbon/junk in the IACV when cleaning it?

nelledge

iTrader: (6)

You're definitely welcome. TB cleaner is fine. I like CRC myself. It's a little more expensive, but it seems to cut the carbon better.

Flanker84

Totally agree.

CRC works like a dream! But you still need an old thoothbrush and "brushie brushie brushie" your IACV. Even you can disassemble it but take note of every part (a spring it's inside of the IACV and it must be assemble again in the correct order). Maybe a work of 2 hours or a little more, also do the bypass coolant... It's the perfect time for it!

Clean it, reset your ECU and after a few miles you will enjoy your smooth idle.

CobraKing

^^^
Just want to update everyone that the P0505 on my wife's car is back after replacing the IACV motor. I did the work myself but didn't perform the 'Idle Relearn Procedure' as the car started fine and RPMs were to spec (or so I thought).

Prior to replacing the IACV, I followed all the steps in the FSM and visually inspected the ECM for any burnt chips too.

Car drove smooth for a week, then P0505 appeared as a 'Pending DTC' and now it's idling high at 1100RPM with a 'Current DTC'.

I'm taking the car to the dealer to perform the P0505 procedure and I'm keeping my fingers crossed that this will resolve the P0505 for good. I'll post an update after a week or two regarding my results.

nelledge, thank you for posting the link to the cached page - I was certain that my original link was working!

TunerMaxima3000

iTrader: (4)

Best of luck Cobra. I am going to take mine apart and try to clean it asap, hopefully this weekend if I can pull it off. I have a can of CRC laying around somewhere, along with my TB gasket, need to find them first....

CobraKing

^^^
Bad news for me brother. I took the car in and the service guy told me that if it's drivable just leave it as is. I still told him to go ahead and perform the idle relearn procedure and he got back to me after an hour saying that the ECM wasn't accepting the relearn and the radiator fans just kept running high. His techinician said I'd have to get a new ECM and harness and both of them advised that the car just wasn't worth it - so I just threw $120 out the window.

At this stage, I advised the wife to drive the car until winter hits and if it gives any further problems we'll scrap it and get a new compact or a used off lease/demo mid size vehicle. I feel bad enough as it is, seeing that she's a new driver and she's gotta drive a finicky car and to top it off it's been giving her a hard start for the past week - will clean the camshaft and crank sensors and hope that it clears up.

TunerMaxima3000 all the best to you bro, drop a note here if you run into any issues.

marky3320

iTrader: (3)

^^Sorry to hear about the dealer not being able to fix the high idle problem. I think my car is having the IACV problem b/c rpm's drop after starting it warm. I hope Tuner's cleaning experience will turn out positive, b/c I don't want to shell out for a new IACV and end up having the ECM fry on me.

TunerMaxima3000

iTrader: (4)

Just did some testing and a very different approach to this problem, I'll post results after a reasonable test period.

-Matt

TunerMaxima3000

iTrader: (4)

sunufabish. CEL came back. Well.... I will put the old one back on with the coolant bypass hooked up, but this makes NO sense, I think something else is causing this issue, my IACV looks like brand new inside, literally, no exagerration, it looks BRAND NEW.

Everything functions very freely inside also. Anyone have any ideas what else could cause this code???

doublea

iTrader: (7)

I have removed my ECM and see the STA509A chip is burned. See post # 1401
http://forums.maxima.org/all-motor/5...roject-36.html

I found an e-bay seller who has 10 of those chips, but there is the following code on my ECM chip, SK4n24 on the first line and underneath STA509A.

The e-bay seller sell the STA509A but on the first line of the chip it is SK 1001. Does anyone know if it's the same chip ?

Here is the e-bay link: http://cgi.ebay.com/NEW-STA509A-/250...ht_4265wt_1360
Found a cheaper price for the chips @ 6.95$ from a seller in Texas

I ordered 2 chip and will solder a socket so if it burned again I will just need to pop the chip and voilà.

TunerMaxima3000

iTrader: (4)

I'll be doing the FSM testing very soon, as well as attempting another idle relearn. I'll update the results.

Thanks for the info above too, +very useful

Mr. Blue Sky

iTrader: (1)

not sure if any of you have checked this thread out, but it has some information on ecu repair services, some DIY repairs that members have tried, etc.
New ecu, Fried in seconds.

hope it helps out those who were looking for this type of information. sorry if it is old news to some.

roberto b. rijos

I NEED HELP PLEASE EMAIL ME AT RIJOSROBERTO2221980@YMAIL.COM IF YOU CAN HELP ME I ACCIDENTLY UNPLUGED THE ECM AND NOW THE CAR WONT START... I TRIED THE BATTERY UNPLUGGING IT TRICK AND WAITING AND STILL IT WONT TURN ON THE CAR TRYST TO BUT IT JUST WONT TURN ON .. THE MECHANIC SYAS HE THINKS THE ECM MIGHT BE FRIED CUZ THATS WHAT HIS FRIEND AT NISSAN TOLD HIM I CALLED A NISSAN DEALER IN BOSTON MASS AND HE SAYS I MIGHT NEED TO REPROGRAM MY COMPUTER.. FOR THE KEYS.. I DONT HAVE HARDLY MONEY AT ALL TO BE PAYING 900 FOR A NEW ECM ACCORDING TO THE NISSAN DEALER IN N.Y ... AND THAT CAR IS THE ONLY MEANS OF TRANSPORTATION MY WIFE AND I HAVE CUZ SHES THE ONLY ONE WORKING RIGHT NOW AND HER JOB IS ABOUT 2 HOURS AWAY I DO WORK FOR A CATERING COMPANY BUT THE BUISNES IS EXTREMLY SLOW RIGHT NOW... PLEASE IF ANY ONE CAN HELP ME FIX THIS CAR I WOULD GLADLY APPRECIATE IT.... MUY CAR IS A 2000 NISSAN MAXIMA

unrealii

iTrader: (8)

1st, the CAPS lock key on your keyboard is broken. Fix it.

2nd, why did you unplug the ECM in the first place? Did you check all fuses?