Idle Relearn Won't Stick On V35 350gt

[o2bfit]

Hello,

A mates 2004 350GT 6MT was experiencing rough idle and stalling at cold startup. Using the Nissan Datascan software, no codes were found and it looked like a dirty throttle body.

Cleaned the throttle body (TB left connected to the harness) and assembled all back together. Performed the Accelerator Released, Throttle Valve Closed and the Idle Air Volume learning (turn key and accelerator pedal methods) and when the car is started, it idles at 725rpm. Turn the key off restart it and it will idle at 900rpm.

Reading the codes, comes up with no errors. The Idle Relearn option in the Datascan software continuously fails unless the "clear self learn" is performed first but still won't stick.

Scouring G35driver has come up with some ideas but none have been successful.

Before booking it into Nissan to perform the learning, does anyone have any ideas?

Thanks

[sonicii]

Firstly the 'clear self learn' is only for the long term fuel trim figures, it doesn't make any difference with the idle air volume learn, so it is unusal that this is making any difference.

Secondly, the accel pedal/key method to do the idle air learn requires exact timing. When you get it right, the RPM should drop down to about 400rpm, then climb to over 1000rpm before settling down at the right RPM, if you aren't seeing this happening, then it isn't actually doing an idle air relearn.

That said, the process via Nissan Datascan should work, so maybe check for other possible causes, like any new vacuum leaks, which might be what was causing your orignal issues.

[o2bfit]

I'm not sure why the Nissan Datascan is failing to set the Idle Relearn. It works fine on my 300GT so it maybe something with my ODB2 adaptor

When I do the accel pedal/key method, I'm getting the correct flashing lights etc. All of the pre-requisites (battery voltage, electrical load off etc) have been checked.

Do you get the all the right learning responses if any of the pre-requisites are not met?

Thanks

[scotty nm35]

It won't stick if there are any errors or faults either.

Probably best to just use the correct tool, Consult 3.

[sonicii]

Do you get the all the right learning responses if any of the pre-requisites are not met?

I don't think the pre-requisites (throttle closed/pedal), will prevent the process running, just mean it might not set it correctly.

As scotty mentioned, there is likely another fault which needs to be resolved before it will work.

[o2bfit]

As a test I tried different timings; 4 secs instead of 3, 10 secs instead of 7 and the MIL light still flashed as it usually does. So it looks like there is no real indicator to whether you get it right or not.

However, after doing the idle relearn, the idle will sit at ~700rpm until it is turned off. I wouldn't expect it to do that if my timing was off.

Putting the ECU in diagnostic mode, it has 10 slow flashes followed by 10 fast flashes then repeats (no codes detected?)

I've ordered a different OBD2 adaptor so see whether that works any better with the Nissan Datascan

[scotty nm35]

The hassle is it isn't OBD2 protocol, no matter how many you try it most likely will never work. I have tested way too many readers over the years, and the Consult 3 is the only unit I can use for diagnostics and relearn procedures.

[sonicii]

I have used the nissandatascan tool to do this process before and it works fine, but that was using the adaptor supplied from them.

Everything the nissandatascan tool is able to do works on my 05 with that adaptor.

It should be fairly obvious when the idle relearn actually runs, rpm drop quite low, then jump up over 1000rpm, then fluxuate a bit before settling down at the correct RPM. If you don't get the timing right with the manual method, you won't see this fluxuation.

[o2bfit]

I bought a new scan cable (A's Dev with FTDI chip) and it works perfectly on my 300GT. Tried on my mates 350GT, still no go.

We contacted Cockram Nissan here in Christchurch who first quoted $100 to put the consult machine on it but when a tech got involved, the price went to $300 and them needing the car for 2 hours. Their reason was they have seen this before with throttle body cleanings and they need to apply a "patch" to fix it.

Has anyone encountered this?

[sonicii]

never heard of that before.. very common to need to do the idle air relearn after a TB clean, but never heard anything about a 'patch'.

Maybe try to get more details about it.

[scotty nm35]

Sounds like bull crap to me. Even if it did need a patch it would only add 5 minutes to an already simple job. (as long as they had the patch file.) More likely they are trying to make some coin out of you incase the car is a headache.

I have sorted many M35's and V35's using consult 2, 3 and 3+, consult 3 is by far the best to use. Other than Nats there is no need to go to Nissan, many decent aftermarket scanners should work. (Snapon, Launch etc)

$150ph with a 2 hour minimum? I need to put my prices up.