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Old 12-26-2011, 07:34 AM   #36
roger 04 rt OP
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Joined: Nov 2011
Location: Massachusetts
Oddometer: 2,304
For those interested in the most arcane aspects of this project, might like to try it or who might offer some insight:

--Both the heater and the sensor are isolated from the case (meaning they are not grounded to the exhaust) in this four wire sensor.

--The wire called signal ground seems to have a 100 ohm source impedance (more to be confirmed), and the open circuit voltage is 140 mV. Since the sensor is isolated from the case, this strongly suggests that the entire sensor signal is offset by 140 mV. I have read that the reason for this offset is to allow shorted and open leads to be detected by the ECU--makes sense. Right now I may have the +Signal going negative relative to the -Signal.

--I have also read that the ECU builds closed loop adaption tables so I should be doing a full reset of the ECU each time I change an LC-1 parameter.

--This signal + side seems, from research, to be routed to a dual comparator circuit that creates a +/- 25mV hysteresis window.

Although things are working really well, I am not convinced I am getting a perfect rich/lean toggle yet so I will probably go and get an oscilloscope so that I can look into all this with a bit more certainty.
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