Hi All..

So heres my question..

What exactly is the difference between the openloop and closed loop.. I know that open is when its cold and closed when o2 sensor gets to 600 degs. I know that closed keeps an ideal systolc (sp) air/fuel ratio but what does open loop do?

Ive been digging around and havent found much info on the specifics of open loop.

Thanks!

 

Well, you have it correct.

When the ECM is in open loop mode, it does not consider the O2 sensor output when it goes to a look up table for the timing and fuel impulse width.

The ECM is in open loop mode during cold starts until the O2 sensor warms up and during WOT runs.



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