Accel/Decel Lambda control Cancelation

[Martin]

How much Accel, or for what period of time, is Accel or Decel needed to cancel the short term trim in lambda control?

It does not cancel if the Accel or Decel is minute.

[RossB]

How are you measuring this Martin? I would have expected that this is determined by the Accel Threshold parameter.

[Martin]

Ive seen it live on ECU manger while driving.


Does Lambda control cancel is there is any decel enleanment?

[RossB]

Yes lambda control will be suspended if there is decel enleanment as well as accel enrichment. There should not be a delay.

[Martin]

Will the short term trim be suspended or reverted to 0?

[RossB]

The short term trim will return to 0. A long term trim would be suspended.

[Martin]

As you can see above, if its very small it doesnt return to 0.

What amount does it need to exceed before lambda trim is cancelled?

[ElectronSpeed]

Disclaimer: I do not know what is in the software now (or even the older versions) and these comments are strictly from observations like yours that I made years ago.

It seemed as though the algorithm ran the Lambda Control routine only when necessary. This would be when a rate condition (the wait between steps) was met. Inside the Lambda Control routine was the check for transient fueling. This meant that if the transient condition was shorter than your rate trim, and it occurred between the rate based updates, it would be ignored.

This is one of the things that drove me to start using shorter rate periods combined with smaller steps.

Eric Schieb
Electron Speed