ZPirate

My car has Nismo cams and occassionally it throws a check engine light for a misfire at idle. My inspection ran out at the end of February. Before I could get it inspected a couple of weeks ago my check engine light came on again. It usually clears up after three or four engine cycles. However, because the car needed to be inspected I cleared codes, but the codes have not reset to ready. I had driven the car at least 100 miles since I cleared the codes, but when I tried to get inspected the codes had not reset. After that I drove it another 30 miles and then checked today with my Scan Guage and it is still reading Not Ready when I scan it. The check engine light has not come back on. Any thoughts? How many miles do I have to drive it to get the codes to reset?

DavesZ#3

iTrader: (26)

It's not miles, per se, it's the completion of a "drive cycle". As a rule of thumb, most people are told to drive 100 miles, two weeks, etc. BTW, the "drive cycle" is a complex series of driving tasks, i.e. - drive for 1 minute at 60 mph, slow to 30 within 5 seconds then drive 2 minutes at 30 mph, etc.

ZPirate

Thanks. It's been almost three weeks since the codes were cleared and it still hasn't reset. However, I don't drive the car everyday and I haven't been on any trips of more than 20 miles. I guess I need to drive it for another week and see if it resets the readiness codes. I guess I need to try to drive it everyday until it does.

ZPirate

After a 30 mile drive this morning the codes finally reset and I was able to get the car inspected. I finally ended up driving approximately 150 miles before I got ready codes.

Q45tech

OBD2 readiness drive cycle is fully explained in FSM. More about number of warm up cycles and 55 mph.............a continuous drive will take forever vs following correct proceedure.

ZPirate

What is FSM? When I talked to my service manager he said it was a complicated procedure to reset the readiness codes and I was better off just driving it until it reset if I was getting a check engine light after I cleared the code. Since I have a ScanGuage I was able to tell when the readiness codes had reset.

__jb

iTrader: (3)

First I've heard of this readiness code... Is this something I can see with Cipher?

I've cleared plently of DTC codes, but I've never seen anything about a readiness code.

DavesZ#3

iTrader: (26)

Here's a good example of what a drive cycle looks like.

http://lyberty.com/car/drive-cycle_maxima.html

It's not for a Z but a Nissan Maxima but you get the idea of what's involved.

__jb

iTrader: (3)

Thanks for posting this... good information... I hunted around a bit and found the info in the EC (Electronic Controls) section of the FSM.

Edit: Apparently the image I posted from the FSM was not related to this issue, so I removed it. Could someone post a page or section number where this applies in the FSM?

Good information. Florida doesn't test for this yet, but I have a feeling that it is coming.

ZPirate

I'm assuming from your post that this page is from a service manual for the Z.
Is that what FSM stands for?

Be glad that Florida doesn't have it. The larger population areas of NC now have emissions testing and I believe next year it goes statewide.

__jb

iTrader: (3)

I think FSM stands for Field Service Manual.

The page I quoted is actually from the 2005 G35 Coupe Service Manual. I have a G, not a Z, but I believe the ECU and DTC codes are identical between the two.

Florida used to have full inspections. I suspect we'll get it again in some form. They're currently trying to get rid of radar detectors and also talking about emissions. That's why I'm interested.

DavesZ#3

iTrader: (26)

FSM = Factory Service Manual.

That section from the service manual is NOT the same thing that the OP was talking about. If you reset the ECU, clear the codes with a scan tool, disconnect your battery overnight, etc. - the ODBII status will report not-ready until a drive cycle is completed. That gives the system time to determine if any problems exist. Otherwise, you could clear a code then drive to the local inspection station and you'd pass with flying colors even though you still had a problem with your car. It has to come ready on its own based on the operation of the engine, emissions systems, etc.

ZPirate

Thanks.

__jb

iTrader: (3)

With all respect, I believe my information was correct. The FSM manual page that I posted showed how to determine if the Readiness Code was enacted without having a scan disk tool. I thought it would help people that don't have a scan tool. I have UpRev's Cipher that is a clone of the Consult-2, but it doesn't seem to show this readiness code. Actually, knowing the UpRev guys, I suspect that it does detect it somewhere, but that I don't know how to find it... nevertheless.

Here is another page from the FSM. Please read the area I highlighted in red. I believe the System Readiness Test (SRT) code is exactly what the OP was talking about.

Please understand that I am not trying to argue with you. I'm trying to figure out what is going on and what is correct.



This FSM page mentions that the SRT code is used to verify ECM self diagnosis (what you are talking about) completion for State emissions inspection testing.

There is much more to this in the FSM. I'm not going to bother posting anything else about it until I'm sure I'm on the right track.

Q45tech

You get a GOLD STAR! Now read on to the desription of the drive cycle necessary.

Once you know the exact miles, number of cranks, warm up time and speed.........you can optimize [minimize] the amount of time/miles necessary to show ready for test.

ZPirate

That is a great point. Had I been able to have some outline of what I needed to do with the car in order to reset the readiness codes (SRT) I possibly could have performed the necessary functions to have it reset/clear faster. Either way I learned something I didn't know through this experience.

__jb

iTrader: (3)

Thanks! I don't get many gold stars on my350z!

I followed up and found the drive cycle description, but it is not as simple as the Maxima drive cycle DavesZ#3 posted above. I'll break it down and post it if anyone is interested. Seems like we might not need it anymore since ZPirate already got his Z inspected.

ZPirate

Yes that is what I was originally looking for, but didn't know exactly what to call it. At this point I don't immediately need it since the SRT finally reset with me just driving the car. Not such a bad thing in my case since I was able to get more seat time in the car than I normally get trying to get the codes to readiness.

However, all that being said I wouldn't mind knowing what the sequence is for future reference if you don't mind posting it.

dboyzalter

iTrader: (3)

And the correct sequence was never mentioned again.