SR20DET Limp Mode

[weirdchris555]

Hey everyone. I was wiring up my consult last night and ran into an issue on my redtop sr20det. The car was fine before this. I have nistune but everything has been working fine prior to this. I ran the wires over from the consult port to the ecu and left them there. I havnt tied into the ecu wires yet. Well I go to start the car and it runs fine. Then after a couple minutes of running it kicks into limp mode. I checked the code on the led on the ecu, but its constantly on. I have no idea where to begin. It happens after reseting the ecu too. I waited all night and it ran fine for a couple of minutes, but if I try to reset it by pulling the battery for a couple of minutes, it starts right up into limp mode. Please help me. Thanks

[OutlawLui]

check your maf, might have a bad connection

[weirdchris555]

Ok ill check it out. Worried something happened when I was tracing wires because everything was fine before all this.

Sent from my SCH-I405 using Tapatalk

[weirdchris555]

Would having no O2 sensor throw the car into limp mode? I did a continuity test from the connector in the engine bay to the ecu pin for the O2 sensor and I'm getting nothing (ran through all 3 wires on the engine bay connector because I couldn't look up which was the signal wire). I had the car running in limp mode, then reached down touched for loose wires and as soon as I got near the O2 signal wire or the Coolant Temp the car kicked back in to normal mode and then when I let go kicked back into limp mode which in turn flooded the engine killing it. Also doubt its the MAF can rev past 3 grand.

[cotbu]

No! It would be open loop mode, not limp home mode! You're ecu you would never get the OK/ready from the 02 sensor and probably not getting the OK/ready from the coolant temp sensor either. Both would make your car run like shit!(too much fuel) but I wouldn't consider it the limp mode you'd have from a faulty mass air flow sensor.

Since you know you have at least one problem, fix it and see what happens or just stop them from shorting out!

[weirdchris555]

Easier said than done. Lol if there's a short its in the pin. Ill check it out later. Also just to verify this is limp mode.

Sent from my SCH-I405 using Tapatalk

[OutlawLui]

Disconnect your maf plug, , inspect it closely and make sure each of the tiny small female plugs are not damaged, if they are than that could be why your getting shitty contact to the maf and going into limp mode. check the maf and o2 grounds for continuity with your multimeter and check your maf and o2 power wires to make sure your getting voltage wen your ignition key is on without staring the car

[weirdchris555]

Yep I just finished doing all that. The MAF had a good ground, got a good power, and had like 10 or so volts on the third wire when the car was just in the run. The o2 seemed to be grounding itself off, so I just went around and made sure everything was good with the ecu wiring and then checked the sensor again and it was not shorting out anymore. I havnt checked the temp sensor yet. I think its a poor connectiom at the ecu plug for at least the o2 sensor and possibly the coolant.

Sent from my SCH-I405 using Tapatalk

[cotbu]

Not limp mode, fucked up wiring! How hard was it to fix the short again, since you know the wires you've touched!
You also have low voltage, mafs should have closer to battery voltage, so should the injectors. 10v at idle or even KOEO is low

[weirdchris555]

I still don't understand why you keep saying its not in limp mode. IT IS. There is no code, the LED is always lit when checking the codes, the fuel pump doesn't prime, running 9.5 A/F ratio etc etc. Its limp mode, directly from the FSM. Now as to why, thats what I am figuring out. Today I am checking the pins. If there is no connection and the ecu sees 0 volts from certain sensors (read zero, not some low value or high value etc), its going to kick to limp. Went and rechecked my MAF i was wrong, it was closer to battery voltage.

[cotbu]

It's not limp mode! By your standards and thinking, a fried ecu, a blown head gasket or blown piston is limp mode. I won't say it again. You have wiring issues, and or a faulty ecu. You are running in the knock map because there are major issues with your car. I can help you. Your problem is not the mafs, limiting your rev too 2500rpm nor do you have codes that say....... well anything! There is no limp mode that stops the fuel pump from priming. I guess you can say, any car that is running messed up is in limp mode!

Then again I would say check the ecu for codes!!!
Take your ecu and put it in another car with the same harness, and try to pull codes

[weirdchris555]

Here's a question for ya. I just ran through diagnostic 24, checking the MAF. So as I previously said, the positive voltage is good. I then went to check the continuity between the ground on the engine bay plug and pin 17 which is the MAF sensor ground. There was continuity. I proceeded to check the sensor wire continuity for the MAF and it was connected to the correct pin 16. I went back to the ecu plug and checked first the ECU ground which is pin 39 and that was a good ground.

Now comes the good stuff. I went to check the ground between what is title "Sensor Ground" which is pin 21, and there was no ground. I was wondering because I am not too sure but are all the sensor grounds run to that pin 21 which is sensor ground? I also checked the signal for the 02 sensor and that had continuity. The weird thing is like a couple of minutes later I double checked the 02 ground and it was fine. So I went back to check the "Sensor Ground" and it was no good.

If someone knows if all the sensors run to that "sensor ground" pin, that would help greatly since I think thats my problem child.

So to summarize, MAF has good continuity to 12 Volt power, to the ecu MAF ground pin 17, and to the MAF sensor signal Pin 16. The O2 has good Power, good ground to the chasis, and good signal wire to pin 19. Pin 21 titled "sensor ground" does not have continuity to a ground.

Just checked the TPS, Coolant temp sensor, and the cas. The coolant and the cas both had good grounds and continuity to the correct pins. The TPS on the other hand did not have a ground whatsoever but did have continuity to the correct pin for the signal. I may try grounding the tps later today as this would cause the issue at hand.

[weirdchris555]

Just as an update I got it out of limp/fail safe mode. I ran through every sensor except the knock sensor checking ground, sensor signal etc. Everything checked out. Went and started the car and it started fine. It was idling fine with a slight misfire occasionally so I went to pull the codes and there were none. Took it for a slight drive and it was running on the rich side. After driving around for a couple of minutes, I parked the car and it fell on its face in the parking lot and died. It had switched back to limp/fail safe mode which I verified by checking the ecu light constantly lit. I am straight up stumped.

As a side note when the car was completely cooled off, there was quite a bit of pressure under the radiator cap...weird.

[GhostlyCoupe]

I had this problem was well recently. It took a lot of digging to find the info about this issue.

The ECU will go into "solid red LED on" mode if it's not able to read the external ROM's containing the tuned maps when using a Nistune/whatever daughterboard.

I was able to fix mine by removing the card and reseating it.

You may not be as lucky and there may be a bad solder joint at the connector that was added.

[GhostlyCoupe]

It's not limp mode! By your standards and thinking, a fried ecu, a blown head gasket or blown piston is limp mode. I won't say it again. You have wiring issues, and or a faulty ecu. You are running in the knock map because there are major issues with your car. I can help you. Your problem is not the mafs, limiting your rev too 2500rpm nor do you have codes that say....... well anything! There is no limp mode that stops the fuel pump from priming. I guess you can say, any car that is running messed up is in limp mode!

Then again I would say check the ecu for codes!!!
Take your ecu and put it in another car with the same harness, and try to pull codes

The SR20DET does indeed have a "limp mode" . It defaults to pre-stored values under certain conditions which are hard coded into the ECU and illuminates the red LED on the ECU.

This is particularly annoying because when an SR20DET ECU is in this "limp mode" the consult port does not function, nor will the self-diagnostic modes (flashing lights) making it that much harder to diagnose.

[weirdchris555]

I had this problem was well recently. It took a lot of digging to find the info about this issue.

The ECU will go into "solid red LED on" mode if it's not able to read the external ROM's containing the tuned maps when using a Nistune/whatever daughterboard.

I was able to fix mine by removing the card and reseating it.

You may not be as lucky and there may be a bad solder joint at the connector that was added.

Hmm I'll have to check it out. Maybe it got jostled a tad. Im pretty sure the solder is good. Like I said it was working fine until I went to wire up the consult. Thank you, I'll look into it.

...and yeah I gave up trying to explain limp/fail safe mode to that kid. Its so unfortunate that consult nor ecu codes work in that mode :(

[cotbu]

This is particularly annoying because when an SR20DET ECU is in this "limp mode" the consult port does not function, nor will the self-diagnostic modes (flashing lights) making it that much harder to diagnose.

This is not limp mode, there is no way for the ecu to protect the engine, if you drive with the ecu in this condition you will blow your engine! Yes, if you have a failed daughterboard installed it can cause the ecu led to stay lit, that is not limp mode.
If you install an ecu that is broken it will not automatically revert to limpmode. If you have detonation with the ecu and the led is lit it will not switch you over to the knock map. Not fucking limp mode

The SR20DET does indeed have a "limp mode" . It defaults to pre-stored values under certain conditions which are hard coded into the ECU and illuminates the red LED on the ECU Yes the ecu does have a limp mode, if you can't read any data from the ecu it is not limp mode, if you have a board installed and you have jumpers set what makes you think it would read from the stock tune. just pull the chips out and you revert back to stock right?

Not a fucking kid! but glad you found new help good fucking luck!

[weirdchris555]

Listen. I am very greatfull for your help. I guess I just don't understand what you are saying. According to both the FSM and Nistune's own communications error pdf my ecu is in limp mode. There is no consult communication in limp mode, nor is there any ecu codes. It just stays lit. Maybe there is a fundamental definition difference between you and me? I have no idea. I'll look at it in the morning its been a long week.

[cotbu]

You listen, the terminology is wrong, fsm, nistune or whatever/ whoever, this is not limp mode!
Fail safe mode would not even be correct as a zilvia.net tech. I would prefer you don't use limp mode to describe your problem. That's all, you just don't understand why, feel me.

I think I know what you problem is, Seriously and I will do it for free, and an apology. Not to me but to the members of the forum. ;)j/k
You probably have a messed up ecu, and some serious wiring issue.
We need to fix and verify or vice versa the ecu issue. You can't put a known working ecu's in your car. Do I really need to explain this????? You have to put your ecu in a known working ecu's vehicle or make a test bench<--- maybe not!
After you determine the condition of the ecu, you can send it to me or post HQ images w/macro and I edit them with pretty colors of things that need to be repaired. Now we'll go through your harness step by step and make repairs. I will hate you after this and only love you again, once you get your car running in tip top shape...! You'll hate me either way, be for warned!

I am rambling on but, just let me know if you want the help and we can start you recovery.
Speaking of recovery, I had this one guy keep yelling at me his phone was "bricked"! Just because he couldn't get into recovery mode, with 3button combo
and because the usb dongle/jig didn't put him into download. I showed him an alternate way to get download mode and he said it worked though a text to me! lol!

GhostlyCoupe, should know first hand that, sometimes they get it wrong!
It worked ! The value data scan had for the tp value was wrong

sorry for the rant and ramble but I know I can help!

[GhostlyCoupe]

You listen, the terminology is wrong, fsm, nistune or whatever/ whoever, this is not limp mode!
Fail safe mode would not even be correct as a zilvia.net tech. I would prefer you don't use limp mode to describe your problem. That's all, you just don't understand why, feel me.

I think I know what you problem is, Seriously and I will do it for free, and an apology. Not to me but to the members of the forum. ;)j/k
You probably have a messed up ecu, and some serious wiring issue.
We need to fix and verify or vice versa the ecu issue. You can't put a known working ecu's in your car. Do I really need to explain this????? You have to put your ecu in a known working ecu's vehicle or make a test bench<--- maybe not!
After you determine the condition of the ecu, you can send it to me or post HQ images w/macro and I edit them with pretty colors of things that need to be repaired. Now we'll go through your harness step by step and make repairs. I will hate you after this and only love you again, once you get your car running in tip top shape...! You'll hate me either way, be for warned!

I am rambling on but, just let me know if you want the help and we can start you recovery.
Speaking of recovery, I had this one guy keep yelling at me his phone was "bricked"! Just because he couldn't get into recovery mode, with 3button combo
and because the usb dongle/jig didn't put him into download. I showed him an alternate way to get download mode and he said it worked though a text to me! lol!

GhostlyCoupe, should know first hand that, sometimes they get it wrong!


sorry for the rant and ramble but I know I can help!


I guess you better call Nistune and tell them to correct their documentation where they refer to this state as "limp mode" then.

http://nistune.com/docs/NIStune_Emulator_Tutorial.pdf

[GhostlyCoupe]

Here is the blurb on lump mode from Nistune. Yes, the car will run while in this mode but it does not run well and will not exceed 3000rpm. I have highlighted the section pertaining to the issue where you can see there is indeed a limp mode that will allow the car to run when a catastrophic issue happens.

The symptoms describe the OP's issues exactly, and this is the fix. That's all there is to it.

From: http://nistune.com/docs/Installation_and_Communication_Diagnostics.pdf



Processor limp mode
Later model ECU's have an internal processor limp mode also. When the program from the ECU chip
or daughter board is not functioning, an auxiliary processor will inject a set pulse width for each
injection regardless of other sensor inputs and ECU program. When in limp mode, this will be indicated
to the operator through the means of a LED in the ECU

Processor limp mode is entered when a major fault has occurred. Major faults occur with anything to do
with the ECU micro code being unable to run. This can be a result of the various factors where the
processor is unable to execute the code properly. If it occurs after resoldering and resoldering then
there may be an introduced problem causing the ECU to go into processor limp mode.
The processor bus on any ECU consists of 8-16 data lines and 16 address lines plus control lines. If
any of these lines is broken or shorted during the installation process, it will stop data flowing correctly
on the lines and the ECU will not be able to run properly.

Symptoms vary depending on engine (specifics covered in the relevant section for each engine) but
one thing is constant across all engines – Consult communications will NOT be active in limp mode. So
you will not be able to connect to it.



Engine running badly is defined as engine may start but idle will be poor and engine will overfuel badly,
resulting in obvious clouds of partially burnt fuel coming from exhaust. Engine may not run at all if
injectors and/or AFM are non-standard. May lean out when rev exceed 2000rpm

Signs of limp mode on common ECUs:

• Check engine light and/or ECU LED will stay on
• Will not be able to connect to the ECU using consult
• When IGN is turned on fuel pump will only pulse on momentarily rather than running for 3 to 5
seconds.
• Engine will not run correctly. Engine may start but idle will be poor and engine will overfuel badly,
resulting in obvious clouds of partially burnt fuel coming from exhaust. Engine may not run at all if
injectors and/or AFM are non-standard. May lean out when rev exceed 2000rpm

If you’ve performed the NIStune board install yourself and the ECU has gone into limp mode then
please check the following:

• Soldering of 20+20 header. Clean flux from all joints and inspect each joint using an eyeglass
and a good light. In particular look for solder bridges between pins and slugs of solder on the ECU
• Check that tracks have not been cut by pushing too hard on the desoldering gun
• Check that you have moved the necessary jumper(s) for the ECU to use the daughter board
• Check the part number on your board matches your ECU number when possible

[cotbu]

They used the term loosely there, and tell you what to check. And it is considered acceptable as they are providing the install guide and can call if fubarred, if they wanted too. This is not a Nistune specific forum, So saying limp mode and using it like the OP did is truly confusing.

The revision on that manual is over due true, but it's theirs and when they help you, they will probably refer to it.

BUT THIS IS ZILVIA!!!

http://i18.photobucket.com/albums/b142/COTBU/caution.jpg

I just wanna comment here, Yes, the car will run while in this mode but it does not run well and will not exceed 3000rpm
This would indicate a mafs malfunction to me, and probably every other member as well, That would be limp mode. When The ecu diagnostic led is lit the car will rev past 3000rpm but clearly have issues, I can probably tell you other things it will do that contradict what the Nistune guide say's. I just wanna say I'm not new to this and just because it's written. documented and spewed over and over doesn't make it law!

Stop calling a F'ed up install of a daughter board, limp mode!

[GhostlyCoupe]

/facepalm

The limp mode is part of the programming in the ECU from NISSAN .. has nothing to do with the daughterboard.

Here are the excerpts from NISSANS FACTORY SERVICE MANUAL

http://i224.photobucket.com/albums/dd31/chrisaz82/ecu.jpg

[cotbu]

I never said our ecu's don't have a limp mode/fail safe mode! Not fucking once. The mode you and the op stated earlier are not the same as what you are posting now! The LED on OBD2 ECU's stay lit till cleared or repaired. ON OBD1 if you have an check engine light or ecu led on while the engine is running, something is seriously wrong! Most likely cause wiring or ecu! Like a fucked up a daughter board install.

Your last post is a normal operating ecu. Not some fucked solder job to a 40pin header
Cali car's are a little pickier but neither one of you newbs are from California



/facepalm

The limp mode is part of the programming in the ECU from NISSAN .. has nothing to do with the daughterboard.

Here are the excerpts from NISSANS FACTORY SERVICE MANUAL

http://i224.photobucket.com/albums/dd31/chrisaz82/ecu.jpg
Stop calling a F'ed up install of a daughter board, limp mode!

[GhostlyCoupe]

I'm sure the guys over at PLMS developments will get a kick out of seeing this thread and being told they have no idea what they are talking about.

I guess you aren't getting how this works. The ECU runs mode 1 diagnostic automatically. I.E. when the ignition is turned off, it returns to mode 1. During mode one diagnostic operation with the engine ON, if there is a fault the ECU will illuminate the check engine light and the red LED and place the car into FAIL SAFE MODE as indicated by the FSM excerpt. This is NOT the same as the mode 1 diagnostic with the engine OFF which is used to check the function of the indicator and LED!

A "f'ed up install of a daughter board" causes a mode 1 malfunction, which causes the ECU to be "stuck' in mode 1 because mode 1 will not clear and allow you to read mode 2 trouble codes unless the fault is corrected. In this case, the fault will remain because the ECU cannot communicate with the daughter board so the LED stays on, and it's stuck and you cannot use CONSULT or other diagnostic modes!

[cotbu]

Stop calling a F'ed up install of a daughter board, limp mode!

An ecu malfunction is a much better term to describe this issue, than limp mode. IMHO
Like I said, if you write the book you can call it what you want!

You keep editing your post, like a 5yr old dude. me too! If you would have put this much effort in you other post,
It worked ! The value data scan had for the tp value was wrong
You probably would have figured it out by yourself
And why not ask NDS to update that data for yuuuuh chea!

PS if pete does come here and pee on me, I'd just cover my eyes and open my mouth and add that knowledge as to what constitutes as LIMP MODE
Then every time someone says they're in limp mode or can't rev past 2500rpm, I'll ask them to check if the ecu led is lit and can you pull codes or connect to consult port?

[weirdchris555]

I can honestly say I have no idea what is going on in here. Lol going to check out the car later with a short drive. It's running properly now but that was at cold startup

[weirdchris555]

Ok its out of the mode. I was finally able to connect my consult port to my laptop. There are no codes (well it says something about new_ok or something along those lines). When its cold, it runs ok and idles ok. I didn't get a log yet of cold, but when warm I did. The 02 sensor voltage was constant at 1.27. Its a new sensor too, which is leading me to the connections. I think its wreaking havoc because when its warm, my wideband is reading around 10 and dipping into the 9s and has a rough and hunting idle. Timing is jumping and so is the maf. Mehh.

[GhostlyCoupe]

Is it showing code 55?

Which ECU are you using and which O2 sensor?

[weirdchris555]

ECU number 62. Stock redtop ecu with a type 3 board installed. No codes. It was running fine with the board etc prior to all of this. Stock redtop o2 sensor (skinny) just got it a couple of months ago from nissanparts.cc When its cold it runs in normal mode. Albeit a tad on the rich side and kinda hard to start. Once it has warmed all the way up though, it goes into that 9.5ish A/F ratio mode with the LED lit. I managed to grab a log all the way up to that mode until the consult port shut down. I have no idea what is going on.

[GhostlyCoupe]

That's all correct.

Self-diagnostic should be showing Code 55 when you hook it up to consult which means no faults.

Is it in fact giving NO codes at all?

[weirdchris555]

I should have clarrified. Code 55 is what it's showing. This is when it's cold. Once it's at operating temp it poops itself. Lol

[cotbu]

Send me your current bin, along w/ what injector size and mafs you're using and your log to: [email protected]

Sent from my Highly Tuned Vibrant!!!

[weirdchris555]

I'll send you my log. It is still running on the stock rom. Haven't tuned for anything yet. Everything sensor/injectorwise etc is stock. Here is a link to the log also. At the end is where it kicks into the LED lit mode and boots me from consult.

Download NIStune_2012-04-08_1843_11.csv from Sendspace.com - send big files the easy way (http://www.sendspace.com/file/vaghv4)

EDIT: It seems at the very end all the sensors go wacky. Jumping all over the place. Even the coolant temp jumps around from upper 100's degrees C to like 60ish. Im at a loss.

[cotbu]

You still have wiring and ecu problems, We need to fix that first. Your problem right know is not tuning, but if you can keep it running normal get it up to operating temp, verify timing then check for boost leaks. I can see before the ecu malfunctions that the mafs, cts etc, get erratic. I'll go through it again and see how soon I see the inconsistencies.

[weirdchris555]

Ok thank you. I'll keep this thread updated. Its the end of the semester and the professors are piling on the work so its tough to find time to work on the car. Trying to get it working again because I do have a track day before the end of the semester. No boost leaks, I'll have to verify the timing.

[cotbu]

Here's what I got, looks like you started the car and drove, ecu was not ready. Idle 1200rpm, cts 49c, TPS .40 but is ok, Timing still fluxing trying to idle 9-15deg and mafs volts a little high. Looks like cas drops out first, but I don't really no what you were doing, a couple time looks normal than really abnormal. Then mafs randomly spike to 3.~ or 4.~ whatever, with no other input from cas, or tps. The oxygen sensor appears to function normal, but the temp is not ideal for closed loop so it never happens. So running rich in this condition would be normal, we need the car warmed up and ecu taking control of things. Get those pics of the ecu up and maybe a video or 2.
4hour job max to get you running right. You could just remove the nistune board and see if it runs any better.

[weirdchris555]

Ok I reseated the nistune board. I'll try today to get a log and a video of the car warming up without driving. Unfortunately it's when it's warm that it dies so we'll see how far it gets. Then I'll pull the board out and try.

EDIT: I just want to be clear, this is not a faulty install of the nistune board. It was installed properly and ran fine for about 2 weeks until I went to wire up my consult port.

[cotbu]

You're new to this, I'm not. The daughter board it self is loosing It's connection somehow to the ecu. I know consult sometimes drops out and you loose a connection. This didn't happen in you log. For you to say "this isn't a faulty install of the nistune board" is ridiculous. any part of the solder work could fail at anytime. The most general of daughter board install guides ask you simply if you start the car and the led is lit then check you solder work I can tell you this, your wiring needs to be checked, but when the led comes on, it's not the same wiring failure that causes the cas, tps mafs and cts to fail. You could have stopped the vehicle at that point pulled codes and probably have code stored for said sensors, but as you continue to drive. The ecu malfunction and codes stored are gone. You need to reinstall the daughter board and fix your wiring. I'm trying to help you with what I see and you wanna tell it's not something i see, well fix it yourself! 5---G

[weirdchris555]

Ok I just went out there and grabbed a log from a cold start until the consult kicked me and went to the red LED mode. No driving or reving etc. Below is a link to the log as well as a video of the whole thing.

Download NIStune_2012-04-09_1106_22.csv from Sendspace.com - send big files the easy way (http://www.sendspace.com/file/yqzvz4)

SR20DET Issues - YouTube (http://www.youtube.com/watch?v=sRPjF6bhD1A)

SR20DET Issues - YouTube (http://www.youtube.com/watch?v=sRPjF6bhD1A)



According to the log, right around the 5 min mark things start to go haywire. My MAF starts to fluctuate, then later my Temp Sensor flies everywhere. O2 sensor shows 0 the whole time too. Also sorry there are no codes during this. I always have the consult ECU messages displayed when all of this is happening.

[cotbu]

You ecu is obd not obd2, nistune will not log errors so again pull the codes manually, I won't go into you missing the codes when they flashed.

[weirdchris555]

Yes it will display codes. For instance I pulled the plug on my AFM, it showed an AFM code within the consult. I'll go video tape that for ya if you want?

[cotbu]

You don't listen worth shit, I give up helping you because your trying to find fault or prove me wrong. I give up totally!!!!!

[weirdchris555]

Im not trying to prove you wrong dude. I have no idea what to tell you. Every time I go to pull codes there is nothing there. Just code 55! I've said this over and over again. I pull them when I notice the sensors start to freak out. I manually pull them as well as check the consult before shutting the car down. Just this time I didn't. It is not booting up into that "processor limp mode", or the red LED mode or whatever you choose to call it anymore. It is occurring when it is warm. All of my wiring was great, the car ran great with absolutely zero problems until like I previously said I went to wire the consult up. If you saw the video, it falls on its face out of nowhere

I've gone through all the sensors except for the knock sensor and all have continuity to the pins on the ecu plug (I checked with a cold engine).

[GhostlyCoupe]

Well the two things that will cause consult to disconnect and the red LED to come on are a fault in the CPU or if the CAS were "disconnected" or was not reading correctly.

Do you have an alternate, known working CAS you can borrow?

If we can eliminate the CAS as a culprit, the only suspect left is the NIStune board or the install.

[weirdchris555]

No sorry I dont. I had it running today and it was kicking into closed loop mode and didn't hit that ecu malfunction mode. I was looking at the coolant temp on Nistune while I was logging the car and it seemed normal, but when I looked at the log later back inside it looked like the temp was getting up to 300ish degrees. It was just sitting around idling. I looked under the hood and some coolant seemed to leak out past the radiator cap. Really confused now.

[GhostlyCoupe]

Was that on an aftermarket gauge or was that what the ECU was reading according to consult?

[weirdchris555]

That was according to the consult using the ECU's temp sensor.

[GhostlyCoupe]

wow that will cause some problems for sure.

Before changing or messing with the sensor I'd make sure to bleed the system really well. A pocket of steam is usually the cause of these sorts of temperature spikes.

Mine was a pretty easy bleed, just let it get full hot then popped the cap and hissssss all the air came out.

Is the sensor itself fairly new? What I would do is get the engine warm to where it reads 300 degrees then measure resistance across the terminals at that temperature. It should be reading NO LESS than around 0.2k Ohms.

[weirdchris555]

Now that I think about it, the reason the system is pressurized is to raise the boiling point according to thermodynamic properties. If my system is not holding pressure, that would lower that boiling point, causing the coolant to be pretty hot. Tomorrow I'm going to grab a pressure tester from autozone and check stuff out. I'll rebleed the system also.

Damn you just popped the cap at full hot? I'd be scared to do that honestly lol

[GhostlyCoupe]

Yeah I turn it slowly to just vent the pressure. I also place a rag over it to prevent coolant spray. They also sell a venting cap where you can just pull the lever to safely vent pressure. I cannot be held responsible if you burn your face off, though.

[weirdchris555]

Ok I'll check it out tomorrow and keep this thread updated. Thanks GhostlyCoupe for you're continuing help.

[weirdchris555]

^Huh? Lol. Im just surprised the ecu and the gauge clusters are that far apart since my gauge cluster was reading where it usually reads right in the middle or just below the middle.

[GhostlyCoupe]

That's to be expected. There's actually 2 temperature senders on the block... one with a single terminal and one with a 2 wire connector. They're both right next to each other.

One gives signal to the ECU and one gives signal to the gauge.

[weirdchris555]

Yeah I knew about the difference I just didn't know it would be that large. And I found the culprit of at least the temp. I was parked on a hill making the highest part of the coolant system roughly at the temp sensors. There was air in the system. Still haven't done a pressure test on the system I'll do it this weekend and see if the car runs better.

[weirdchris555]

Bled the system. Was quite a bit of air. The weird thing is when I am watching the log and recording it while the car is running, temps are normal. When I go to play the log back later they are pretty high.

Anywho, it started going into that ecu processor limp mode again back to square one. Going to hunt down a new ecu I guess for now to check stuff out

[weirdchris555]

I did find something out today. The image on the board is for a blacktop ecu rather than a redtop. I know about the difference in o2 sensors, I disconnected it but not that it would matter it would just stay in limp mode.

The car starts and runs then after 5 or so minutes from a dead cold start, it kicks into the ecu malfunction mode and kicks me. There are no codes up to this point either. I can turn the car off, let it cool down for a tad without disconnecting the battery, and then start it again without a problem. It the just repeats itself once it warms up with no codes (well, code 55). I have no idea. Its like there is a fuse or something electrical that overheats and then crashes until I let it cool down, almost like a bad switch. Any help is apreciated

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[weirdchris555]

Trying to find someone to reprogram my Nistune board in the USA. AVP hasn't gotten back to me since my initial attempts to contact them on Friday. If I can't find someone in the area with a spare ecu to check, I'm going to revert it back to the stock jumper position.

[sr20redbird]

/facepalm

The limp mode is part of the programming in the ECU from NISSAN .. has nothing to do with the daughterboard.

Here are the excerpts from NISSANS FACTORY SERVICE MANUAL

http://i224.photobucket.com/albums/dd31/chrisaz82/ecu.jpg

This might have just helped me with mine! Baahaha

[Matt191]

Did you ever get this figured out? My car is doing the same thing and literally have no idea what is going on but my car revs and everything but as soon as it gets put under a load, 3 grand limit is all....

[weirdchris555]

Sorry, I never got it fully figured out. But it was ecu related. Myself and an electronics guy checked it out and we could never figure it out. No burned/broken traces. Even had voltage checks across joints on the pcb thanks to the guys at Nistune. A new ecu and nistune install solved the issue. Hope that helped

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[Matt191]

Thank you for the reply I'm glad you got the issue sorted out by some way. There is no one within probably 500 miles of here that even owns an sr (as far as I know) so I'm gonna have to throw money into an ecu.... And I might just fry it when I put it back together....