closed loop/open loop ECU and piggyback comp
Thread Starter
Joined: Nov 2001
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From: Melbourne, VIC, Australia
closed loop/open loop ECU and piggyback comp
Hi all,
I was wondering -- if piggybacks (e.g. VAFC) alter 02 sensor input signals to get different output signals, how does that react under closed/open loop? It sounds like settings would only work for one case or the other....
Also, one more thing, can someone clarify for me: open loop means using 02 sensor (right? Since the ECU is "open" to environmental input) and closed loop means using raw fuel map values (i.e. not using 02 sensor, hence "closed" to the outside world)... is that right? I've heard otherwise....
I was wondering -- if piggybacks (e.g. VAFC) alter 02 sensor input signals to get different output signals, how does that react under closed/open loop? It sounds like settings would only work for one case or the other....
Also, one more thing, can someone clarify for me: open loop means using 02 sensor (right? Since the ECU is "open" to environmental input) and closed loop means using raw fuel map values (i.e. not using 02 sensor, hence "closed" to the outside world)... is that right? I've heard otherwise....
Honda-Tech Member
Joined: Jan 2002
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From: Sydney, Australia
Re: closed loop/open loop ECU and piggyback comp (ckkl)
upside down - open is from ECU data
closed is from O2 input...
most piggy backs go for the MAP adjustment (which is the most influential ECU input to determine pulse width of injector duration and hence A/F ratio)
t..
closed is from O2 input...
most piggy backs go for the MAP adjustment (which is the most influential ECU input to determine pulse width of injector duration and hence A/F ratio)
t..
Honda-Tech Member
Joined: Oct 2001
Posts: 4,611
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From: Severn, MD
Re: closed loop/open loop ECU and piggyback comp (tinkerbell)
tinkerbell is correct: When the ECU is in Open Loop mode, it is using internal pre-programmed values to control injector PW. When the ECU is in Closed Loop mode, it is using the O2 sensor for trimming the PW to maintain good emmisions.
Also, the ECU mainly relies on MAP & RPM input to intially 'look-up' these values for injector PW...its then trimmed by other sensor inputs, such as ECT, IAT, etc.
Also, the ECU mainly relies on MAP & RPM input to intially 'look-up' these values for injector PW...its then trimmed by other sensor inputs, such as ECT, IAT, etc.
Thread Starter
Joined: Nov 2001
Posts: 257
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From: Melbourne, VIC, Australia
Re: closed loop/open loop ECU and piggyback comp (EE_Chris)
<Also, the ECU mainly relies on MAP & RPM input to intially 'look-up' these values for injector PW...its then trimmed by other sensor inputs, such as ECT, IAT, etc.>
What's ECT and IAT?
What's ECT and IAT?
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