SR20DET Limp Mode

[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

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



SR20DET Issues - YouTube



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

Sent from my SCH-I405 using Tapatalk 2

[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]

Originally Posted by 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

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....