Have you tried pulling the (AT) tranny codes via the FSM?

Also, for verification limp mode is different than what you're experiencing, by definition from the FSM.

Limp mode will literally get you killed in an intersection. It will not allow the throttle to open more than 10%, and it will take a long (seriously) time to get there. As in if you actually got to 2500 RPM, you were trying for a very long time and ants were passing you when you were trying to get there.

With all that said, I believe 100% it is a MAF /IAT issue.

An no, the VAFC will not lose its settings, but that can easily be verified by going in and checking the +/-%.

And as far as ECU swapping, they are all plug and play, no "wiring" to speak of. It's like plugging in a huge USB connector, there are no bare wires, and a large "clip" that connects and ensures a strong connection ... so I wouldn't let that freakn you out.

And for clarification, everyone here that has entered limp mode/fail safe, it is very different than not being able to rev past 2500 RPM. I've driven to work on a dead MAF, and it's fine. It would take me the better part of the workday to actually get to work in FS mode, much less get home at a reasonable hour.

 

I'm not changing my auto ECU... what's th way around that with the MAF not being the problem as I changed it and its still doing the samething

 

So is it in limp mode/fail safe or is it just not revving past 2500 RPM? I would check the MAF wiring, and do you have the VAFC wired in?

VAFC wiring can cause both no rev past 2.5k and FS, but again they're different.

If it is wired in, I would go over the wiring (specifically the MAF wiring). And also the TPS signal you're using for said AFC.

Incorrect MAF wiring will cause no rev past 2.5k
Incorrect TPS wiring will cause Fail Safe.

Sometimes the ECU needs an extra ground or 2. I needed to do that when I wired my AFC & WB in. BUT, it was because I kept getting fail safe due to TPS signal noise.

I wouldn't assume changing the MAF will completely rule out the MAF, expevially if you have an AFC in there.

I would try and get the actual codes too (ECU codes before tranny codes).

Tranny codes will set you into FS mode since they work off of the CAN lines and TPS/APPS.

 

According to the shop, its all tranny codes no tps or anything but ill try messing with the tps

 

Are your VAFC wires sodered or twist and taped? I would check everything MAF related if you just cant rev past 2500. Manny had a similar issuse in his 5.5 gen. He said it was TPS

 

Yea he was tellin me.... I definately don't have a extra one of those lol

 

Do you have a MAF code? If you don't have a MAF code, then I doubt its the MAF or circuit. It could be the solenoids. You could try replacing the solenoids with a resistor of equal value. Kind of like what is done for the knock sensor, but with a different value resistor because the solenoids will surely have a different (much lower) resistance.

I would compile a list of codes so we can see what systems may be causing the limp mode condition, and go from there.

 

Vafc seems to be working fine...

 

lemme ask this... could it be that my TPS needs to be recalibrated???, if im coming off the hwy and i even press in on the clutch to downshift the car cuts off due to it revving so low...

 

If you mean solenoids as in tranny solenoids Ghustle threw his solenoids away and will probably never deal with them again...ever.

If it were your TPS, 10MPH would seem like 150 ... because you would then be in fail safe mode. There are APPS/TPS and their inverse signals. If APPS and TPS are not within a certain % voltage wise, the ECU sees this as a bad thing and will shut you down into FS mode.

I think you need an OBDII reader or Consult type logger like UpRev. This way you can see & log all these parameters and troubleshoot accurately instead of setting off shotgun rounds in the dark.

Why not putter onto Autozone or any place with a code reader and get the codes read.

Or do the pedal dance for codes.

Codes codes codes.

 

^ +1. codes would help

 

So u ready 4 this.... I just went to advance auto and they don't have a scanner smmfh... only in Maryland and th way the car limps and vibrate I'm not even gona chance another auto store as it probebly gonna b the samething.... car service here has to be theee worste

 

Maybe call the next place before you head out

 

Too bad you don't live around here. All the maxima people who live in this area (including me) have an obd2 scanner... What ya'll MD boys don't believe in scanning your codes to figure out issues?

In any case, getting the codes will very likely point you to the culprit. There are only so many things that can cause limp mode and if it's throwing a code for one or more of them, focusing on those specific codes should bring you closer to solving the problem.

 

well, datdude just came by and drove it to his advance and there is 23 codes lol.... like 4-5 of them are tranny selonoid codes but i believe the culprit showed its face with these codes...
P0102
P1224
P0221

i wanna say those are MAF's and TPS codes

 

23 codes? lol thats gotta be a record!

 

thats what the dude at advance auto said ... like i said like 6 of em were like tranny selonoid (same code), and another 6 was some other tranny code, my old o2 sensor codes from the 1st week of me owning headers lol then those 3

 

i never knew TPS can go bad by sitting over time??? or i wonder is it that my MAF code is causing the TPS code to show also?

 

yea they are .....thats what it said on the scanner
we do...who told u that lie

 

i told u mine went bad in the middle of me running a group of g35's and Z's done...it gave no warnings at all
it wasnt that bad...it had the every code like twice

 

hey hustle i did some research for you theirs this guy Tavarish he's done 6 speed swaps 02-03 im sure he could help u with your problem his number (908) 247-1055 his AIM, sn is tavarish8712

and here is an ad he put up not to long ago hope this helps u out http://forums.maxima.org/northeaster...-tavarish.html

 

So, assuming manny drove to the shop, it wasn't in TPS "fail safe I cant open my throttle past 10%" mode, but seems more like it is along the lines of the MAF.

So, now would be a good time to read the fresh set of codes which hopefully erased the "stored" codes that were semi irrelevant to the problem at hand.


EC 129 has the different FS scenarios and when the TPS is affected there are very informative descriptions, and there is a big difference when comparing MAF to TPS FS modes.

http://www.nicoclub.com/FSM/maxima/2003/ec.pdf

I just hope the ECU isn't looking for TPS feedback from the TCU.

 

my man, 2 thousand grand lol

 

200,000

Or 2k .. cripes

 

Yea this guys rates anit that bad when i go to ny to visit the fam i mine have him do the full 6 speed swap for me

 

naw only 2000

 

nice

 

Don't work, changed the MAF and TPS and still not revving

 

Did you have any luck trying to get a hold of Aaron to get his thoughts?

 

yea he has no idea what could be the problem also... it revs so low that if i come to a stop and the clutch all the way in it will just shut off, sometimes ill turn it on and it will turn on and shuts right back off... on start i swear the rpm needle will go as low as 5rpm (yup you heard me right 5) the weirdest ones is when i down shift and it will shut off ill just keep the clutch at the engagement point and it will just turn itself on and go to its correct rev (yea that i have no idea how it happens), i know my previous TPS is still in working condition even though i changed it but i am totally confused and i am actually starting to give up on it... im going to try and take it to the dealership to see if the TPS or MAF (whichever) needs to be recalibrated...

 

When you hit 2500, does it bounce off it as if youre hitting the limiter?

Also you didnt try unhooking the battery for a few seconds did you?

 

yea its like a rev limiter at 2500..... yes i unhooked the battery for about 5-7 mins, samething

 

You didnt clear the codes after you did it did you?

 

this is about to be maybe the dumbest question i will ever ask period (seeing as though all the "sensible" ones still dont add up)

here goes.....
Can these stupid GSP axles that cause the car to not only vibrate but shake like a magnitude 20000 earthquake (i dont even know how i find a way to laugh through this) be the cause for the car not revving like that... i know its a dumb question and feel free to ignore it but im just mentally drained

 

yes, i used a scanner and cleared the codes after every last thing i did, everytime

 

I think you're thinking too much without actually diagnosing, not trying to offend you or say something bad my dude, but it happens to all of us when we're in situations like this. I suggest you look up all the codes and see what they actually are and how to fix them they should point you to the culprit, I don't think the ECU is going to limit the revs without giving you the code for it. It really sounds like a MAF problem to me. Since you say you cleared the codes have they came back? If so which ones? The quickest codes to come back is the culprit in my book.

 

The codes are for maf and tps....

 

Test them and fix them as per the FSM.

 

The p0102 code is for maf low circuit signal or something to that effect... I gets that's moreso with the wiring vs the maf as I've used a MAF that was brand new

 

Check the wiring ... Also check the MAF voltage, etc. via the FSM. Puppetmaster had a good write-up I thought.