Having experienced this issue in the past week like so many from what I’ve read. I set out to find an answer, or at least make sense of the issue, and in doing this, I hoped to find a fix. I feel I may have achieved both. The thing with this is you can’t keep testing it over and over to make sure it does work. So, here’s my current angle on this. My experience to date is 10+ years building, and modding cars primarily engine related. I’ve been programming ECMs for 4+ years.

It would appear that by using a spray chem. to clean the TB some how alters the idle through a mechanical issue at first, and not ECM. I have a few theories as to how, but again without repeated tests there is no way to find out for sure. My though is that some how the vapors from the chem. spray remain in the intake as they do with most cars. This is part of the hard start that follows a throttle body cleaning usually. For some reason these vapors must stay longer due to design, or affect something down stream of the throttle body. Theory #2 is that the spray some how affects the throttle plate operation for a short time. One way or the other a high idle is produced. Now this is where it gets tricky. The ECM is still fine at this point. It knows the idle should be at X range and it’s not. This basic idle range is hard set in the Flash rom chip in the ECM. Once the code is set. This is when the ECM gets messed up and goes crazy. We must remember the basic principles of computers and such. These are items that only do as they are told. They have chips that have info that is permanently set meaning no power is needed to retain the info. This info just like all other computer languages and is basic hex. Now with any computer the more complex the program and number of lines of code the more you increase the odds of error in the program. I feel this is the key to this P0507 code. The programming of the ECM some how conflicts with itself when this code is set, and causes it to go crazy. Much like your house hold computer. As Windows became more complex so did the issues, and the number of issues. Same goes for cars. Once it’s set you have enacted a glitch that just doesn’t go away. The car knows it’s suppose to idle at X range, hence the code keeps getting set. It’s just gone stupid, and doesn’t know how to control the idle. I think the throttle blades are set to achieve 900-1000RPM at idle with no interaction from the ECM, which is why it’s at that range. Even clearing the code the ECM still has left over hex junk in the memory confusing it. This is why relearning doesn’t work most of the time. Now replacing, or reprogramming will work because this fixes the glitch. Just like rebooting your home computer. So, how do you re-boot this computer? First of all nothing that still allows the ECM to have power will work. You have to undo the bat. cable and leave sit for about 2 days to allow all, and any power that can maintain memory on the Ecm to drain and clear all, and any info that the ECM has ever seen, or knows. This leaves you with nothing but the flash program in the mem-cal that was put in from day one. Again this is my theory. I had the glitch, and tried everything known to man, then I let it sit for two days with the bat. Cable off and now it works fine. It ran better than before it developed the high idle issue. Of course I think there maybe something wrong with the knock sensor, or crank sensor. Because the car runs like a bat out of hell sometimes, but most of the time it just goes, there is a def. difference. Had this problem on a Saturn. The knock sensor sometimes picked up the engine noise as knock and retarded the timing. Replaced it with a updated sensor and WOW.

Again this is all my opinion and have no test dta to back it up 100%

 

never thought id see the words "saturn" and "WOW" together. hahahahaha



well aside from not having a max for a couple days, it definitly doesnt hurt to try something like this... good info

 

Do you have the ability to edit OUR prom's?? (e-prom, prom, rom, whatever we use) If so what program are you using and what interface are you using to edit this info??-- I would really like to change my shift points, but refuse to pay $300 to have it done.....(others more than likely would like to change their rev limiterrev limiter)

Sort of, but not really... More of an A/F ratio issue.

I'm assumming the code is for unable to control idle or something of that sort??
That's beleiveable RIGHT AFTER start-up if the engine hasn't sat long enough after cleaning for the vapors to exit.
High idle or other issues should only remain until the spray is gone. After a few seconds you would think it would have all been sucked in. Esp. with a few throttle snaps or @ WOT. Any remaining amount would be to little to affect much. so I highly doubt theory #1 would cause a high idle for very long.
Messing up the EGR system would play a bigger role, IMO. But that would throw its own code.





With your background you should have the tools to check TPS position, etc. Simply see if the TPS is in the correct position or unhook it and see if your idle changes. - You should also know this, but not all cars control control idle by throttle position. Alot of newer cars have another piece that opens and closes to divert air into the intake while the throttle remains almost completely closed.


So basically you're saying that once the code is set the ecu doesn't try to control idle anymore??? Sounds like the way it was programmed to me. Not really an error, but possibly to prevent loobing or stalling at idle, incase of vacuum leak, etc.
It may just go to a predetermined position and remains there until the problem is fixed and computer reset. It's probably even in a TSB somewhere that after fixing the error that the ecu must be reset.


If the ecu stopped trying to control idle, then the ecu won't try to relearn idle until reset.

I deleted half and that's still a confusing mess. If I'm understanding this, basically what you're saying is once this code is set that the ECU stops trying to control idle????
Um, you have been done this how long????? You have wasted a good part of your career waiting around. Simply unhooking the battery and pressing the brake pedal will draw all the power from the ecu's capacitors... Also I've been told that you can touch positive and negative together and it will pull all of the power out of the capaciters. (It suppossadly sends all the power straight to ground.)
If the crank sensor isn't working one of two things will happen. depending on make/model.
1.) The car will go to sequencial fuel injection. (send fuel to all of the injectors at once since it doesn't know which cylinder to fire)
2.) Won't start.
Should set a code.

 

5thgenmaxima,


You spent so much time taking , but offered no answers. If you could be so kind as to give use the definitive answer as to the how and why. That would be just great.

 

Well I'm not sure what the code means, but I'm going to make 2 assumptions

1.)The code means unable to control idle.
2.)Once this code is set the ecu stops trying to control idle.

Figuring these assumptions on your problem is true, the how is #2. and the why would more than likely be because the ecu doesn't want to keep trying to control idle when there may be a vacuum leak, or other problem that is causing a high/low or spuratic idle. Trying to allow more or less air into the intake constantly will just cause a higher loob....
That's my guess.



Anyhow, you say you've been programming ecu's for 4 years?????
Do you have a rom editor to dump info into the nissans ecu??
If so what interface and program are you using?

this may be a FAR stretch, but I MAY be able to get my hands on the latest update software from Nissan, if I could somehow convert/copy the files onto a USB drive during the day, that would be golden..... I don't know alot about programming though, so you would have to walk me thru it. (The update info is on a card that the consult-II reads, but is downloaded directly from the computer)

 

Logic would point to what your thoughts are on the P0507 code. The issue is that the reason for the code being set in the first place place, and the effect that occurs from cleaning the TB doesn’t make sense. That’s what has so many stumped. That’s why my org. post had what seemed to be crazy ideas as to the problem, but given the spec . nature of this problem, just about anything is possible. It’s a think out of the box deal.


I do not have software that will allow me to pull the ECU program. Sorry for not being more spec. on the programming. I have messed with OBD II for a little while now, but on GM cars LS1 Edit, LT1Edit, and for the older OBD1 cars I use Datamaster as my data capture software, and tunercat to convert my bin files to readable/programmable info. For the OBD I cars a simple flash chip 29c256 works just fine and keeps you from having to purchase a UV eraser. I use the pocket programmer for the OBD I style. It’s a cheap little sucker, but it works great. I am looking into getting what is needed to mod the ECU on the Maxima, I just haven't had much time, and I just got the car about 3 months ago.

 

Wait a minute, do we have a solution here? Trying to keep it simple..... I just had the P0507 code a few weeks back and although others had their ECM replaced I had mine reprogrammed by the Stealership ( 1 hour labour later!!! ). We need a test subject, someone currently with the P0507 code or dare I say someone to clean their TB which will surely conjure up this code, then instead of bpe383's "let stand for two days with the battery disconnected" they use this "Simply unhooking the battery and pressing the brake pedal will draw all the power from the ecu's capacitors..." from 5thgenmaxima

 

Yeah it's a good idea. I would like to see some else try it as well. It's free, and easy. Would really hurt the dealer.

Like I said the ECM is not flashed so by cutting power you will restore the ECM back to it's org. state. Simple reset deals by pushing the gas pedal do not have the same effect because I feel left over bits of info are always left over even after you clear the code.

I agree with 5thgen on the affect of pushing the brake pedal, but given the nature of this issue. I just feel that discharging the electric system quickly could be a problem. It's just a guess, and caution thing for me .

This car seems to sensitive I'd just rather take the time and baby it. I have more time than money.

 

I have that code right now from cleaning my TB. I have unhooked the battery last night and pumped the brakes to get the charge out. I will let you guys know in two days if the car is back to its original state.

 

Please let us know.

I have one other question. How did you manage to open the TB to clean it?

1: Did you force it open with your hand, or other object?
2: By turning the key on and having someone hold the pedal down while you cleaned it?


This is important because most people it seems force the thorttle open, where as I had a friend push the gas peddle while the key was in the "on" pos. This opens the blade as if you were driving just without the engine reving.

 

I forced it open with my hand. That was the biggest mistake I have ever done with this car. My A/C doesn't work now either...

 

This is why I say that I'm not a big fan of hitting the brakes to discharge the system These cars are past super sensitive. They are like trying to eat ice cream and have it not melt in the desert at high noon.

 

Try to not to worry to much. I'm hoping this no power for atleast two days thing will fix anything electric related.

 

Can you tell me if this fixed the problem? I know this posting is 6 years old but I am running into the same issue.

 

I cleaned the MAF with CRC maf sensor cleaner too. I also cleaned the TB with a diff. product and after putting everything back together, the ses light came on. Since I have a code scanner too, it also threw code P0507 with a higher than normal RPM at idle. I did the idle air volume learning procedure and cleared the code with scanner. Problem was fixed.

 

I also realize this thread is really old and there are tons of other threads just like it......but

Realtor - did ever come back up? I did the same as you, cleared it with a code scanner, did the IAV procedure and it was fine....until i shut off/turned on the car. Idle issues continued. I drove 25miles and that damn check engine light came back on...

 

I had this problem as well, P0507 code after cleaning the throttle body. Tried the IAV procedure which only worked while the car was on, once I restarted it, the idle went high again and the code (P0507) came back. Instead of chasing it down, I just replaced the throttle body and it fixed the problem. I didn't have to do any idle reset procedures for the new throttle body. Plug and Play, restarted the car and the idle went back to normal. Cleared the code, and it never came back--I've been driving about 2.5 years since all of this happened.

My advice: if you perform the idle IAV procedure and it works, UNTIL you turn the car off/on again, then go get a replacement TB.

 

Hi did anyone ever get back with the battery drain thing to say if it worked. Having same trouble tried reset,no dice. Nissan mech told me had to be relearned by dealer. Thanx