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What does "Clear Self Learn" do?

The "Clear Self Learn" function clears ECUs memory. The ECU constantly monitors the engine and adjusts some parameters to achieve predefined conditions i.e. A/F ratio, knock. Some of that data is store in the memory so it can quickly readjusts itself. This function clears this data.

Sorry, I know this is an old thread but could someone clarify some questions I have?

1)Is Clear Self Learn done before an Idle Relearn?
2)Am I required to do an Idle Relearn after initiating a Clear Self Learn?
2)Is Clear Self Learn done with the engine running or just the "key on" position?
3)Initiating Clear Self Learn, does the engine have to be at operating temperature?

thanks everyone
tubbedz

1) No.
2) No.
3) Either.
4) No.

Clear self learn just clears long term fuel trim figures. These are figures the ECU calculates and stores over time to accommodate for differences between what the ECU 'thinks' is the correct fuel mix from data it receives from sensors, and what is actually the correct fuel mix.

IAVL isn't affected and has no impact on long term fuel trim.