IAVL failed

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abosaad
Posts: 5
Joined: 12 Jun 2021, 15:26

IAVL failed

Post by abosaad » 19 Jun 2021, 08:28

I'm working on a friend's 2010 Altima 2.5. He cleaned the throttle body and was complaining of high idle.

I use DataScan III on a windows 10 tablet, it connects quickly to the ECM/TCM/BCM/IPDM no problem.

My issue is that I cannot compete the idle air learning procedure.

The first time it failed I thought it was because the engine temperature gets too hot (over 95 C) during the learning procedure.

So I waited for the car to cool down and I started it again just as the temperature reached 80 C, thinking I could complete the procedure before reaching 95 C. But it still failed (the engine temperature didn't get too hot).

I then disconnected two coils (cylinders 3 and 4),but that also didn't help.

I don't know what to do know, what I do from here? How can I complete the idle air learning process?

Thank you

Tom
Site Admin
Posts: 627
Joined: 09 Dec 2011, 19:17

Re: IAVL failed

Post by Tom » 07 Jul 2021, 14:53

Did you make sure there is no electrical load? Turn off air con fan, radio, lights etc.
Is the steering wheel in straight ahead position? So the power steering pump (if there is one)is not creating any load on the engine.
Did you check for any air leaks in the intake? Even a very small air hose will fail the IAVL.

abosaad
Posts: 5
Joined: 12 Jun 2021, 15:26

Re: IAVL failed

Post by abosaad » 09 Jul 2021, 23:49

Tom wrote:
> Did you make sure there is no electrical load? Turn off air con fan, radio,
> lights etc.
> Is the steering wheel in straight ahead position? So the power steering
> pump (if there is one)is not creating any load on the engine.
> Did you check for any air leaks in the intake? Even a very small air hose
> will fail the IAVL.


Thank you Tom. I made sure that there was no electrical loads as everything was off and the steering wheel was dead center. However I can't guarantee there was no vacuum leaks, I couldn't hear any air leaks anyway.

What's your advise here?

Tom
Site Admin
Posts: 627
Joined: 09 Dec 2011, 19:17

Re: IAVL failed

Post by Tom » 24 Jul 2021, 00:45

Look for any loose hoses that could be leaking air. Sometimes people forget to reconnect some after throttle cleaning.
Clear self learn before starting the IAVL procedure.
Try running the IAVL with ignition ON and engine OFF first. Then with the engine ON.

Sometimes when the idle is too high the procedure will fail because the air flow reading is out of specs. Try to lower the RPM by disconnecting some coils or restricting the air flow.

There is also a chance there was some damage done to the throttle body when it was cleaned.

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