Annoying SMOG issues, ECU only passes 3 out of 7 monitors... HELP!

[zomgdrft]

Basically my ecu/car is driving me nuts. When I bought it, it had been sitting without a battery for a good year or so. I fixed it up, put a new battery in, and everything drove great. However, I'm having the hardest time passing SMOG due to the fact that i keep getting CEL/MIL failure on the test. It states that it cannot complete all "internal tests, blah blah."

I took it to mechanic shop and had them run a readiness test to see which monitors/tests mine had passed and which ones had not.

Readiness Test Results
Misfire status = Complete
Fuel Status = Complete
Comprehensive Status = Complete
Catalyst Status = Not Complete
Heated Catalyst Status = N/A
Evaporative Status = Complete
Secondary Air Status = N/A
AC Status = N/A
Oxygen Status = Not Complete
Oxygen Heater Status = Not Complete
EGR Status = Not Complete

Now, I've driven my car a good 600 miles or so since the rebuild. I think that would've been long enough for all monitors to pass. I have no CEL codes or any issues with the car AT ALL. The only thing that's missing from the car is the AC condenser, so the AC does not work.

I don't see how having no AC would cause it to not clear all monitors but at this point, I'm pretty tired of this and just want a resolution. I've researched online and spoke to a mechanic who confirms that Nissan had some problems with early model OBD2 ecu's (96-97). Stating that their drive cycles where very annoying to get all the monitors to pass. I've even tried calling a dealership to see if they'd put it on a dynometer to run it through the drive cycle, but they stated they don't do that :(

Ugh, I'm at a loss, and I need this to pass in order to reg my lovely new vehicle.


PS - I've ordered an OBD2 plug-in which connects to USB on my Sony VAIO laptop. I ordered it from AutoEnginuity so it comes with some pretty quality software. Hoping that will help me solve some problems. Any help would be great guys, thanks.


EDIT - Also I meant 4 out of 8 monitors on thread title ;)

[C. Senor]

ok so you've put 600 miles on the rebuilt motor, how many miles on it since you've charged the battery. once the battery looses power or you change power all those readiness tests reset...so you have to drive the car a while, for the most part i'd say a good 50 miles of both street and freeway miles....some cars can take a few hundred miles so hope your not one of those dudes, but yeah if you just charged/changed battery drive those 50 or so miles and then take your car straight to the smog station without turning it off.

[zomgdrft]

ok so you've put 600 miles on the rebuilt motor, how many miles on it since you've charged the battery. once the battery looses power or you change power all those readiness tests reset...so you have to drive the car a while, for the most part i'd say a good 50 miles of both street and freeway miles....some cars can take a few hundred miles so hope your not one of those dudes, but yeah if you just charged/changed battery drive those 50 or so miles and then take your car straight to the smog station without turning it off.
Thanks for the input but I don't think you read my initial post to closely ;)

I didn't rebuild the motor. I bought the car, the motor was fine. It just had a lot of front end damage and was just missing a battery and been sitting for a year or so.

Anyways, I put a new battery in after fixing the front end damage, and have driven 600+ miles on the new battery. The ECU has not gone through all the monitors and I want to know why. Is it possible I have a bad ECU or what? The car drives fine, though. No issues at all.

[mrmephistopheles]

your EGR is stuck or you have a vacuum leak, which is causing your ECU to fault.
Also verify that your ECU isn't in test mode.

[punxva]

you could have also just gotten the Nissan Consult software and cable, since the consult gives your basically all the control that you would need to troubleshoot

[zomgdrft]

your EGR is stuck or you have a vacuum leak, which is causing your ECU to fault.
Also verify that your ECU isn't in test mode.
What do you mean stuck? A blockage somewhere?

[drift freaq]

What do you mean stuck? A blockage somewhere?

EGR valve is a valve that opens and closes allowing exhasut gas to recirculate or not. If its stuck it could be stuck open or closed. quite often vacuum lines going to it get old and crack causing it not to open. That could be your problem and its relatively easy fix.

[zomgdrft]

Well I have't physically tested the EGR valve yet or anything, but I did go over the area and the hoses where it's located. Everything seems to be in OK order. I didn't notice any cracks or breaks in the hoses leading to it or from it. I spoke with oen of the guys at the nissan dismantler here in town and he said he's had to replace bad ecu's in the first year OBD2 240sx's before. I'm leaning towards that I probably have a bad ECU :( Which is odd, because it still functions fine, I had a CEL a month back from a bad front O2 sensor. I dunno :\

[projectRDM]

In thirteen years I've never heard of a bad ECU unless it was damaged by neglect.

The unready codes are very hard to clear, I've got the sheet from Nissan that describes the steps, it involves driving in each gear at timed and speed intervals with the A/C both on and off in different situations as well as varying engine load. Odds are you haven't driven enough at the right speeds to clear them yet. I just did this on a friend's car that wouldn't pass, a full day of driving to the exact recommended procedure cleared it all out. The CONSULT will clear stored codes but not the unready codes.

[C. Senor]

you know what, go somewhere that can clear the codes, have them clear the codes, or disconnect the battery for a little while and then connect again and drive for like 100 miles....try to drive atleast 50 miles the day you take your car in and dont turn it off..its worth a try...there are some cars that for some reason everytime they are turned off the readiness codes turn off, that could be a possibility also... honestly in some random cars, there's been really severe conditions that takes somewhere north of 500 miles before the codes set, i dont know how much a new ecu for an s14 is, but i think drivin a 100 miles or so would be cheaper....assuming that works.

[shayrgob240]

you know what, go somewhere that can clear the codes, have them clear the codes, or disconnect the battery for a little while and then connect again and drive for like 100 miles....try to drive atleast 50 miles the day you take your car in and dont turn it off..its worth a try...there are some cars that for some reason everytime they are turned off the readiness codes turn off, that could be a possibility also... honestly in some random cars, there's been really severe conditions that takes somewhere north of 500 miles before the codes set, i dont know how much a new ecu for an s14 is, but i think drivin a 100 miles or so would be cheaper....assuming that works.

wow! don't post advice if you don't know what you're talking about...seriously! Why would you clear the codes? And why would you disconnect the battery? The car will have to go through its monitors ALL over again, which isn't what this dude wants. What he needs is to pass emissions.

One thing to keep in mind is that NOT all the monitors have to pass. YOu are allowed 1 or 2 failed monitors ( i forget exactly how many you can have that haven't passed).

But basically you need to go through the proper drive cycle like previously stated and try and fix whatever issues you are currently having w/ the car.

Also, just b/c the MIL isn't on, doesn't mean that there isn't a DTC.

PEace

[zomgdrft]

wow! don't post advice if you don't know what you're talking about...seriously! Why would you clear the codes? And why would you disconnect the battery? The car will have to go through its monitors ALL over again, which isn't what this dude wants. What he needs is to pass emissions.

One thing to keep in mind is that NOT all the monitors have to pass. YOu are allowed 1 or 2 failed monitors ( i forget exactly how many you can have that haven't passed).

But basically you need to go through the proper drive cycle like previously stated and try and fix whatever issues you are currently having w/ the car.

Also, just b/c the MIL isn't on, doesn't mean that there isn't a DTC.

PEace
Well before I ordered this OBD2 USB adapter (which hasn't arrived yet) I took it to AutoZone and scanned it with the cheaper one there. No codes came up. Said all was ok :( It didn't scan the MIL readiness monitors, however, because it was kind of a ghetto device.

[C. Senor]

wow! don't post advice if you don't know what you're talking about...seriously! Why would you clear the codes? And why would you disconnect the battery? The car will have to go through its monitors ALL over again, which isn't what this dude wants. What he needs is to pass emissions.

One thing to keep in mind is that NOT all the monitors have to pass. YOu are allowed 1 or 2 failed monitors ( i forget exactly how many you can have that haven't passed).

But basically you need to go through the proper drive cycle like previously stated and try and fix whatever issues you are currently having w/ the car.

Also, just b/c the MIL isn't on, doesn't mean that there isn't a DTC.

PEace


hahaha i dont know what i'm talking about...you should heed your own advice..i work at a smog shop smart ass....i think i know exactly what i'm talking about....i was telling him to reset the codes because sometimes they are fixed by reseting them....you cant just tell him one things will work for every car....you cant tell him the ecu is bad, you cant tell him those sensors are messed up because thats a possibility as well, you cant tell him the wiring went bad to those sensors because that could happen as well, that could be the cause as well....that's why i told him to reset it, disconnecting the battery by the way makes all those readiness sensors reset themselves, yeah a little info for you right there, or clearing all the codes will reset the readiness test not just the engine codes, but i figured maybe resetting the codes and driving, which is what you have to do to set the readiness codes, would be cheaper than doing everything else, and if it didnt work he'd lose like half a day, and IF, remember i said if, it worked he would save money....but that's just advice from some one that "doesnt know what they are talking about." good luck with that od2 reader you bought, i hope you find the problem so you can get your car registered...oh and it depends on the car on how many readiness test he car can have not set to pass, could be anywhere from 1-3, just so you know for next time.....and yes i know that just because the MIL(check engine light) light isnt on it doesnt mean that there isnt a DTC (diagnostic trouble codes for those reading that dont know what those stand for), but you can have a dtc that is continiously being monitored and still be fine, also just so you know...anyways ways long enough school session/rant....like i said earlier hope you find your problem.

[zomgdrft]

So, would resetting the ECU, using the diagnostic screw on it, clear those readiness monitors? Or do I have to literally disconnect the battery? I did reset it with the diagnostic screw a few weeks back (before the major driving) when it gave me a bad O2 sensor CEL.

[projectRDM]

So, would resetting the ECU, using the diagnostic screw on it, clear those readiness monitors? Or do I have to literally disconnect the battery? I did reset it with the diagnostic screw a few weeks back (before the major driving) when it gave me a bad O2 sensor CEL.

Guy above is full of shit. Some cars may clear the unready codes when unplugged but ours do not. Disconnecting the battery will only reset your clock, nothing else.

[C. Senor]

Guy above is full of shit. Some cars may clear the unready codes when unplugged but ours do not. Disconnecting the battery will only reset your clock, nothing else.


you're very observant i am full of shit, i just ate some rice and meat, and i do actually have to go to the bathroom....so apparently its time for class again...i was talking to our tech today about your exact issue, he said dont bother trying to reset it, i had misunderstood him from before, but if you have this problem right now, you might have it for a while, but found out that you can apply for a waver, since you drove your car for 600 plus miles, fill the application and they will more than likely give you a waver for two years, so that means that they will bypass smog this one time and let you register it, but after two years you will have to smog your car again, though that next time if it does not pass you have to fix it, you get no second waver, that is assuming you live in california...i dont know but hell just might be there...lol, but yeah dont bother resetting sorry, either do the waver or fix it are basically your only options....oh yeah now for the schooling part.....and the reason for me quoting homeboy above....no matter what any ob2 vehicle....ANY....disconnecting the battery will reset the readiness test "codes"...just for calrification they're not really codes, just signals....anyways sorry for the misdirection before, this time i'm 234 percent sure of everything i just wrote....good luck with your smog issue....sorry i cant find the exact application for that waver, you can ask yuor smog station people but heres the link to the bar http://www.smogcheck.ca.gov/stdhome.asp
they also have a financial assistance if you need it, the repairs can sometimes get costly and electrical repair is fairly expensive.....once again good luck

[zomgdrft]

you're very observant i am full of shit, i just ate some rice and meat, and i do actually have to go to the bathroom....so apparently its time for class again...i was talking to our tech today about your exact issue, he said dont bother trying to reset it, i had misunderstood him from before, but if you have this problem right now, you might have it for a while, but found out that you can apply for a waver, since you drove your car for 600 plus miles, fill the application and they will more than likely give you a waver for two years, so that means that they will bypass smog this one time and let you register it, but after two years you will have to smog your car again, though that next time if it does not pass you have to fix it, you get no second waver, that is assuming you live in california...i dont know but hell just might be there...lol, but yeah dont bother resetting sorry, either do the waver or fix it are basically your only options....oh yeah now for the schooling part.....and the reason for me quoting homeboy above....no matter what any ob2 vehicle....ANY....disconnecting the battery will reset the readiness test "codes"...just for calrification they're not really codes, just signals....anyways sorry for the misdirection before, this time i'm 234 percent sure of everything i just wrote....good luck with your smog issue....sorry i cant find the exact application for that waver, you can ask yuor smog station people but heres the link to the bar http://www.smogcheck.ca.gov/stdhome.asp
they also have a financial assistance if you need it, the repairs can sometimes get costly and electrical repair is fairly expensive.....once again good luck
I've never heard of such an application. Has anyone else? That would help me out greatly if it does exist! Thanks

[C. Senor]

i'm serious, if you in cali. watch take like 5 min of your time, go to your smog station ask them and they'll tell you, if i remember correctly you will have to fail smog first, as the financial assistance requires you fail the test first. but i know for a fact that there is a waver for that, we just let a guy know about that, after driving his mercedes for 500 miles and none of the readiness sensors were set....ask for the 2 year waver.....dmv is nice like that and give you 2 years to hopefully fix your car...i know dmv nice.

[zomgdrft]

i'm serious, if you in cali. watch take like 5 min of your time, go to your smog station ask them and they'll tell you, if i remember correctly you will have to fail smog first, as the financial assistance requires you fail the test first. but i know for a fact that there is a waver for that, we just let a guy know about that, after driving his mercedes for 500 miles and none of the readiness sensors were set....ask for the 2 year waver.....dmv is nice like that and give you 2 years to hopefully fix your car...i know dmv nice.
I think I found what you're speaking of.

Repair Cost Waivers are available to everyone who has a vehicle that fails a biennial inspection and
who's emission system has not been tampered with. It allows a vehicle to be registered without passing its
Smog Check inspection by providing a temporary (two year) extension of time to complete all emissions-related
repairs. To qualify, at least $450 in emissions-related repairs must be made to the vehicle at a licensed Smog
Check station. The waiver may only be used once by a motorist during their ownership of the vehicle.
According to that I'd have to spend $450 at a licensed maintanence station in order to qualify for the 2-year waiver. No thanks.

[C. Senor]

oh wow, you found it, i didnt know you had to spend 450, ask the people at the smog station to help you, a tech told me that it also applies after driving it so many miles, you can also cal the BAR, about that, because i swear some guy got that waiver because his car wouldnt set those codes....i'd look into it a little more, sorry i cant give you more info on that because we dont deal with the applications and such.

[projectRDM]

Have a 'friend' write up a bogus repair bill exceeding $450 and turn it in, just make sure your tracks are covered if they follow up on it.

[zomgdrft]

Well I have the OBD2 device and have run some scans over the past day or two. It still wont complete 3 of the monitors :( There are no DTC's and no other obvious signs of problems. I'm so freaking confused.

[drftwerks]

what are the motitors it wtill wont pass, haha there is alot of misss info in this thread

[zomgdrft]

The monitors it wont pass are listed in the first post. Nothing has changed over the past week or two. ANd it's irritating the hell out of me.

I just tried jacking the rear end up in my driveway and running through the drive pattern again but still no dice :mad:

[drftwerks]

you have to find the process for running the moniters. clear them all, and get a scanner i sugest snap on modis or solus.

moniters run in an order i belive, and when it cant pass one it will stop.

using the scanners i have posted, you can check the pids and see what they are doing.

[zomgdrft]

you have to find the process for running the moniters. clear them all, and get a scanner i sugest snap on modis or solus.

moniters run in an order i belive, and when it cant pass one it will stop.

using the scanners i have posted, you can check the pids and see what they are doing.
I've already bought an OBD2 USB adapter with very good software that lets me all the monitors, etc from my VAIO. I don't know about clearing monitors, as I've never really done that. I have the Auto Enginuity software, which as far as I can tell is pretty detailed and very verbose for it's low cost. Should I pull the battery for a night and start over the next day?

My EGR is fine, simply because I can't smell anything out of the ordinary and my gas mileage is perfectly fine. I replaced a front O2 sensor, but I reset the ECU after installing it.

[drftwerks]

yes you can reset by disconnect the battery,

test your o2 by looking at the sig wave form and rev it up fast)stomp the throttle), it should change (go up) it should also do so in a fast motion not straight up but verry fast after you hit the throttle.

make sure the heaters on them are good as well.

you have front o2 and rear right check both,

when your under the car hit the cat, if it rattles then its time for replacment

[zomgdrft]

yes you can reset by disconnect the battery,

test your o2 by looking at the sig wave form and rev it up fast)stomp the throttle), it should change (go up) it should also do so in a fast motion not straight up but verry fast after you hit the throttle.

make sure the heaters on them are good as well.

you have front o2 and rear right check both,

when your under the car hit the cat, if it rattles then its time for replacment
Ok, I'll unplug it tonight. Would having it un plugged for 12 hours be enough for it to reset? ALso, wouldn't I get a DTC if there was a problem with either of my O2 sensors, I understand that my MIL may not come on, but I literally have no DTC's what so ever :( ?

[drftwerks]

monitors my not set dtc in all cases, in all reality you need a proper tool to get through theese

[zomgdrft]

Well I've pretty much come to the conclusion that my ECU is toast. There is simply no other explanation. I went into further advanced features on my AutoEnginuity software and it won't even show any sensors or temps or anything for more than a split second. It'll show the proper number, for like a second, then it'll just flash off, as if I turned off the ECU or something. It's as if my ECU is frozen, or something. Which is why I think the monitors will not continue, and are just frozen with the 4 I have passed. I also tried disconnecting it from the battery for an hour, to fully reset, and that didn't help either.

I wanted to make sure it wasn't my software or OBD2 scanner, so my friend brought his 96 Civic over and I ran all the diagnostics on it flawlessly. And now that I've seen it actually fully work, I absolutely love this software and OBD USB device.

I'm trying to locate a 96 ECU to see if that will change things. If anyone wants to get rid of one let me know.

[Jesses240]

I also have the Auto eng software, and honestly from a professional standpoint, unless you buy the 800$ package its not really worth it... but if your not professional every day use then its great.

I have only seen 1 ecu that has actually been bad that replacing it fixed the problem, it is very rare.

Worst comes to worse, just find someone who has the same 240 as you and borrow trade ecu's for a day.

Most of the time when I take customers car through deq after fixing issues/dtc's... I don't have to drive more than 10 miles to get enough monitors set...

you can have up to 2 monitors not set here in oregon. Don't know about your state.

[zomgdrft]

I also have the Auto eng software, and honestly from a professional standpoint, unless you buy the 800$ package its not really worth it... but if your not professional every day use then its great.

I have only seen 1 ecu that has actually been bad that replacing it fixed the problem, it is very rare.

Worst comes to worse, just find someone who has the same 240 as you and borrow trade ecu's for a day.

Most of the time when I take customers car through deq after fixing issues/dtc's... I don't have to drive more than 10 miles to get enough monitors set...

you can have up to 2 monitors not set here in oregon. Don't know about your state.
Yeah, the $200 package, which I got, is fantastic for non-professional users, like myself. But yeah, as far as doing it for a living, obviously something higher-end would be required.

But yes, I thought it was quite strange that I wouldn't pass my monitors in a short amount of time. So right now I'm trying to locate another ECU for a 96 Manual. Does anyone know if a 97-98 manual ECU would work? OR are things to different in those models? Thanks

[zomgdrft]

I would just like to bump this, to let everyone know I bought a different ECU from a fellow member on here (drifto-san, thnx btw) and just installed it and took it for a drive tonight (1am) and only after 10 minutes of driving it's already passed 5 monitors!!! Including the EGR monitor and O2 heater sensor (2 that didn't pass with the old ECU).

So it is now confirmed that my ECU was in fact, BAD ! :D ECU's do go bad, especially OBDII ones, let this be known!

[shayrgob240]

I would just like to bump this, to let everyone know I bought a different ECU from a fellow member on here (drifto-san, thnx btw) and just installed it and took it for a drive tonight (1am) and only after 10 minutes of driving it's already passed 5 monitors!!! Including the EGR monitor and O2 heater sensor (2 that didn't pass with the old ECU).

So it is now confirmed that my ECU was in fact, BAD ! :D ECU's do go bad, especially OBDII ones, let this be known!

hey man! I just wanted to thank you for letttiig us you what the issue was. Good job on your diagnosis!

[excelS13]

this is happening to me now, should i repalce my ecu?