Does PCM use high or low signal O2 feed?
11-11-2004, 04:04 PM
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Looking at a diagram for bank 2, it looks like current flows from high (pin 66 green/yellow) to low (pin 26 grey/black). So if I want to run the car with only a single o2 sensor, can I tee PCM feed pin 69 (violet) into PCM feed 66 (green/yellow), and leave the sensor side of pin 69 disconnected?
11-11-2004, 04:12 PM
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I believe it uses the "high" and the "low" both,
like instrumentation amp style, to take out any
ground offset error.
If you're thinking about the lean cruise thing,
I believe it's a mistake to expect that straight
voltage offsetting will do the job; the O2s really
operate by switching and not continuous analog
style. You probably will need to force open-loop
and then just dial in your open-loop fuel/air table
in the regions that represent "normal cruise".
like instrumentation amp style, to take out any
ground offset error.
If you're thinking about the lean cruise thing,
I believe it's a mistake to expect that straight
voltage offsetting will do the job; the O2s really
operate by switching and not continuous analog
style. You probably will need to force open-loop
and then just dial in your open-loop fuel/air table
in the regions that represent "normal cruise".
11-11-2004, 04:30 PM
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I just want to bypass one, so I can play around with the fuel delievery on one bank without it creating ltrim issues. Should I patch the high and low side over then? If you think about it, the high is probably the reference and the low is probably the return, right? I don't know much about electronics though. 
