2011 Nissan Rogue

I have just cleaned a throttle body on my Rogue at 133,000 miles for the first time (removed it for cleaning). It was a long overdue maintenance (TB was dirty to say the list).
According to manuals EM, EC it required some re-learning procedures.
I have followed all of them:

Accelerator Pedal Release Position Learning Procedure.
Throttle Valve Closed Position Learning

And tried Idle Air Volume Learning, but was unable to get a MIL blinking.

I do not even know if first 2 procedures did anything meaningful, it is not possible to verify.

But I have noticed that the ECM definitely forgot previous idle settings, because the idle at engine start was rough with 2000 rpm but in 2-3 mins it got back to normal 700 rpm and was stable and smooth afterwards.
All symptoms of dirty TB disappeared.

My question:
May I assume that the ECM readjusted/relearned idle air volume on its own without those re-learn procedures?
It seems that it indeed self-adjusted but want to hear from experts on this subject.

I have eventually completed the Idle Air Volume Learning procedure.
Initially, I warmed up the engine by idling, but EC recommends to drive vehicle for 10 minutes (this part I ignored). One of preconditioning for this learning procedure is "Transmission: Warmed-up". This time I did it as recommended.

It was probably the tranny causing your issue, they can take God's own long time to get warm at idle with no load. Driving them isn't really required to get it warm, blocking the wheels and setting the e-brake to let it idle 8~10 minutes in gear will also serve.

After all learning procedures that I have completed, my understanding that the Throttle Valve Closed Position Learning was the only procedure that needed after the TB disconnection and cleaning.
I do not see any difference between idle rpm / Absolute Throttle Position before running the Idle Air Volume Learning and after. I might be wrong, but it seems that the ECM is capable to adjust idle air volume on its own.

The IAVL matches the MAF sensor electrically to the ECM, to account for any circuit tolerances in the MAF. When they're mismatched it makes a great deal of difference in both performance and fuel mileage. So whether your particular MAF needed it or not, it should always be done after any work on the induction system. It does not happen automatically.

2011 Nissan Rogue manuals:
EM-32:
" ... Perform the “Throttle Valve Closed Position Learning” when harness connector of electric throttle control actuator is disconnected. .."
"... Perform the “Idle Air Volume Learning” and “Throttle Valve Closed Position Learning” when electric throttle control actuator is replaced..."

EC-513:
" ... Throttle Valve Closed Position Learning is a function of ECM to learn the fully closed position of the throttle valve by monitoring the throttle position sensor output signal. It must be performed each time the harness connector of the electric throttle control actuator or ECM is disconnected or electric throttle control actuator inside is cleaned..."

According to this manual the “Throttle Valve Closed Position Learning” requires the engine start and warming it up, not like some videos or Internet instructions (Nissan/Infinity) state that the ignition switch ON is sufficient for this procedure.
So, the “Idle Air Volume Learning” that I ran was unnecessary in my case but it will not harm. (again, I make this conclusion only based on the manuals not on any kind of experience).

Now I understand that those 5 accelerator pedal quick pumps within 5 sec create an air flow to read the MAF.

Questions regarding this process (VStar650CL's input is especially welcome):
- Is it best to remove the throttle body to clean it or OK to do it in place with cleaner? If cleaned in place, I would think it's not a good idea to bathe the unit in cleaner and then let the engine swallow all the residue?
- If cleaned in place I'd think it best to just do an internal wipe down with cleaner and a lint free rag?
- Any tricks or issues in removing it and reinstalling it after cleaning?
- Once cleaned, will the ECM handle the re-learn itself? Can/should I use the re-learn procedure in CVTz50?

Thanks Everyone...

phmichel wrote: ↑

Mon Aug 09, 2021 9:55 am

Questions regarding this process (VStar650CL's input is especially welcome):
- Is it best to remove the throttle body to clean it or OK to do it in place with cleaner? If cleaned in place, I would think it's not a good idea to bathe the unit in cleaner and then let the engine swallow all the residue?
- If cleaned in place I'd think it best to just do an internal wipe down with cleaner and a lint free rag?
- Any tricks or issues in removing it and reinstalling it after cleaning?
- Once cleaned, will the ECM handle the re-learn itself? Can/should I use the re-learn procedure in CVTz50?

The crucial areas to clean are the back side and trailing edge of the butterfly, so if you can get a toothbrush or wool dauber into those areas with the TB in place, then cleaning it in situ is fine. A brush with plastic bristles is better than a rag for cleaning the trailing edge, since the stuff back there can get crusty. Don't sweat the residue, the junk that builds up is primarily carbon. It's not very abrasive and the cats will digest it without any issues.

Vis the IAVL, if the last IAVL was done with the TB clean then it may not need it, you're just restoring cleanliness. But it never happens "automatically", and as I mention frequently, MAF's drift electrically. So performing a periodic IAVL is a good idea regardless of other factors. Our policy at the dealership is to do one with every tune-up or induction service to keep the ECM calibration "up to date".

I recently cleaned my throttle body after 12 years of never doing it. First and foremost, I never really had problems with it, so I thought I be proactive and clean it for the heck of it. AND the mass air flow sensor which I have done many times before.

But I didn’t want to take the throttle body out because I had a hard enough time removing that hard plastic connecting intake tube or whatever. Unlike others, this plastic is very rigid. And I didn’t feel like putting the bolts back a certain way and re-torquing it either. Probably the very reason I never went through with it because of the tube removal at least for me.

So I just tried cleaning it where it was located, but unlike the videos on YouTube, the plate wouldn’t open even with pressing on the gas pedal which was bummer. So I just use throttle cleaner, a rag, and a toothbrush to clean it. The plate and edge.

The only problem was I got the damn code after cleaning. So I cleaned my mass air flow sensor repeatedly. After a few days I realized one of the tubes came off.

After reinstalling it, smooth sailing just like BEFORE ever since.