I have searched & read tons & tons of threads on this & still I have no definitive answer. I can't imagine no one knows for sure when the ECU goes into open loop.

I have seen some people post that it's based on many factors, but most ECU's have a TPS % reading that ALWAYS kicks it into open loop, independent of any other factor. I am going to tune with a AFC & simply need to know what this # is, so I don't tune any of the closed loop map.

PS if we figure this out maybe we can sticky this thread or put it into the FAQ's

Thanks,
Ed

 

The car is in open loop the instant it's started.

 

Open loop at wot.

 

billman, No it's in closed loop at idle.

mrfixit687, yes but it is in open loop before 100% TPS position.

OK, let's have people answer who have some data behind this. Logs of the ECU with Greddy EU or AFC or something.

 

edomund
if u start it up cold.. its in open loop till it warms up

anyone that works for honda can test this.. since i can on any toyota using a scanner..

 

OK but I'm not really concered with if it's open loop during warm-up. I'm trying to determine at what TPS % it always goes into open loop for tuning open loop with piggybacks.

ed

 

Buy a scan tool.

 

there is really no magical number. open loop is determine by load which is calculated from RPM, VAC and Throttle. if you have a wideband, you can see when open loop is activated. i would say it's usually between 15%-20%, but don't take my word for it.

 

hondaf1, I have read before from 1 guy that after 25% TPS it is in open loop regardless of map or rpm & after 5000rpm it is regardless of tps & map. So I am pretty sure there is some set #'s where it's always open loop. I need some others to confirm these #'s. Once I hook up my innovate 02 I will be able to help confirm I just think others must have already tested this.

sqtb, thats not really a very helpful post. I'm sure there are already people on the forum with scan tools who checked this already.

 

ed, I've got an ecu scanner that lets me know when its in open/closed loop. Ill try to check for you next time I drive the car (which is rare weekends)

I met you at the last hooters meet btw, dont know if you remember. Also my scanner shows % throttle position/engine load so ill try and see if there is any corrolation.