Quick AFM Question

[Turbo Habanero]

So i've been trying to find out the answer to this for awhile i'm hoping someone can help me out.

So when i unplug my AFM is the car sappose to keep running or is it normal for it to die out?
If it is dying out what is that a sign of? As my car will die when i unplug the AFM.

I heard unpluging the AFM sends the ECU into TPS/STA signal mode?
Something i read that i'm trying to learn more about.

Thanks in Advance Jordan.

 

[Nick M]

It should run. It means you need to pull DTC's. You are feeding the ECU too much false information, and it can't keep the car running without its primary input.

 

[hvyman]

Should just be able to idle tho. Wont rev. Atleast my car wouldnt and friends when there afm went out.

 

[Turbo Habanero]

hmmm crap lol... i don't have any check engine light and it seems to be running pretty good (atleast as far as i know)

---------- Post added at 03:01 PM ---------- Previous post was at 02:59 PM ----------

It should run. It means you need to pull DTC's.

I do not know what this means. Please Explain

 

[jetjock]

On a GTE it should continue to run and be drive-able to 3000 rpm. On a GE it'll die...

edit: He means check codes. DTC is Diagnostic Trouble Code.

 

[Turbo Habanero]

On a GTE it should continue to run and be drive-able to 3000 rpm. On a GE it'll die...

edit: He means check codes. DTC is Diagnostic Trouble Code.

Oh thank you for clearing that up.

So i went and checked out some things changed some vaccum lines and now it runs while at idle with it unpluged although i did not test if it would rev or drive like that

 

[bioskyline]

it will drive but barely, it wont boost though. this is often called "limp home mode". it will move but not very fast

 

[3p141592654]

The GTE ECU needs to have code 31 set when the AFM is unplugged to keep running. Sometimes it will not set right away and will die. When it is set, the injector duration is set to two values, 2.76ms on idle, and 4.36ms off idle not including the time for injector opening which depends on battery voltage. It also sets a fuel cut flag at 3k rpm. That is enough to make it drivable as JJ's youtube video showed.

 

[jetjock]

Yes, as I've said many times the TPS needs to be working when in Fail Safe for a 31 and STA is used for starting. Hence the "TPS/STA" thing the OP mentioned. Actually, iirc, STA is always used to emulate Ks during a start whether the AFM is working or not because airflow is too low at cranking speed for a reliable signal.

And as 3p pointed out the system can't supply Fail Safe protection unless it's in Fail Safe. It's why the possibility of a shifted sensor must not be ignored when troubleshooting. Put simply just because there's no codes or light doesn't mean everything is OK.

 

[SupraBro]

Great info guys!!