Page 1 of 1

Question of Open and close loop logic

Posted: Sun Sep 28, 2025 12:52 am
by DumaTec
Hi I am confused about the Honda FD2 TypeR ECU's open and close loop control logic.

According to the Hondata manual, there are two conditions that the car will go into open loop
-Car is in WOT/high load condition
-The WOT adjustment table value needs to be below 0.85 lamda otherwise it just stays in close loop

This raised some questions.
1. Why the WOT adjustment table covered low load & RPM area which is supposed to be close loop?
2. Does the WOT adjustment act like a multiplier or AFR target table?
3. Someone told me that there are three modes which are: closed loop (lamda=1), WOT closed loop (Has an AFR target until lamda<0.85), and the

Re: Question of Open and close loop logic

Posted: Sun Sep 28, 2025 12:56 am
by DumaTec
Sorry for
DumaTec wrote: Sun Sep 28, 2025 12:52 am Hi I am confused about the Honda FD2 TypeR ECU's open and close loop control logic.

According to the Hondata manual, there are two conditions that the car will go into open loop
-Car is in WOT/high load condition
-The WOT adjustment table value needs to be below 0.85 lamda otherwise it just stays in close loop

This raised some questions.
1. Why the WOT adjustment table covered low load & RPM area which is supposed to be close loop?
2. Does the WOT adjustment act like a multiplier or AFR target table?
3. Someone told me that there are three modes which are: closed loop (lamda=1), WOT closed loop (Has an AFR target until lamda<0.85), and the
Sorry for the unfinished sentence. Here's the completed one
3. Someone told me that there are three modes which are: closed loop (lamda=1), WOT closed loop (Has an AFR target until lamda<0.85), and the open loop whenever lamda<0.85. I wanna confirm if this is true and can we change this logic in Hondatat?

Re: Question of Open and close loop logic

Posted: Mon Sep 29, 2025 9:10 am
by Spunkster
What is the issue you are having?