What is Adaptive Control?

[DetroitSVT]

Ok this maybe a very nubie question but hey that's what I am. I learning to tune using Don Lasota's DVD and Tuning Manual. In the 2nd chapter (of the DVD) explaining how to set up a base tune it says that the first thing to do is to turn off the "Adaptive Control", but does not explain what the purpose of adaptive control is.

I guessing it is a program that allows the engine to learn what the air fuel ratio should be at idle.

Can someone explain what "adaptive control" is? Also if I turn it off when setting the base turn for idle and part throttle do I need to turn it back on afterwards?

 

[watman02]

adaptive control is closed loop operation its the ecm learning fuel strategy and idle control. this must be turned off to get the open loop control you need to get the maf transfer function dialed in at idle and while free revving.
you DO turn this back on before you drive it.

 

[DSG2NV03]

adaptive control is closed loop operation its the ecm learning fuel strategy and idle control. this must be turned off to get the open loop control you need to get the maf transfer function dialed in at idle and while free revving.
you DO turn this back on before you drive it.

+1. I believe it's not forcing open loop per say, but it is disregarding ECM corrections. This way you can use STFT to dial in your MTF.

 

[Don 95Vert]

Adaptive control is different than Open Loop. Adaptive control is a process used by the PCM to correct for small changes in engine parts, such as wear to the MAF, dirty MAF, etc. The PCM looks at short term fuel trims and as they slowly drift away from optimum, a correction gets stored and applied - these are the long term fuel trims. You have to shut of the adaptive (LTFTs) when you are dialing in the MAF TF because if not, you end up chasing your tail as the PCM changes along with your changes. If you don't set up the adaptive fuel tables correctly, then in some cases the PCM will apply adaptive changes to WOT - in older PCMs this is the only time stock 02 sensor data changes WOT fueling. This is not a good thing (2011+ being an exception because they have wideband 02 sensors) on a modified motor because it may apply changes to make the motor leaner.

Open loop means the PCM is using MAF data only all the time with no input from the 02 sensors.

Hope this helps,

Don

 

[DetroitSVT]

Thanks for the help! I understand why adaptive control must be turned off much better now, but I don't know some of the acronyms used.

@Don, What does LTFT sand for regarding adaptive?

Also, what is STFT and MTF stand for?

 

[Don 95Vert]

LTFT=Long term fuel trim
STFT=Short term fuel trim
MTF=Mass air transfer function

 

[DetroitSVT]

LTFT=Long term fuel trim
STFT=Short term fuel trim
MTF=Mass air transfer function

Cool! Google wasn't much help with those.

 

[ZOSO]

the one thing that I have ran into is the more mods you do and change the set-up the harder it is to tune and keep the adaptive working smoothly. I just keep mine off and have yet to have an issue. My afr and stft are perfect. No need for ltft/adaptive.

 

[DetroitSVT]

My car is setup for autocross ESP class so the engine is stock other than a K&N air filter and removal of the smog pump. So I believe for me using the Adaptive Control is a good idea. I just didn't understand what it was.

 

[kxt]

i run adaptive off all the time also.