"Terry Schwartz" <tschw10117@aol.com> wrote:
: Having worked in engine controls for some time now, let me tell you my
: understanding on how O2 sensors work. I'm on the periphery of this, not
: directly involved in engine management system design. But I've been
: designing electrical systems for engine powered machines for several years
: now.
: The sensor oscillates. It's output is part of a tank circuit. It does not
: put out a DC voltage, rather a ac voltage. The computer reads the amplitude
: and frequency and interprets this as the CO level.
: So there is no way to gang or parallel sensors (simply anyway) and keep the
: ECU happy.
: Now if the ECU were set up to read both sensors to begin with, that is a
: different story.
Terry,
Thanks for the info. If this is the case, then it certainly wouldn't
as straightforward to do some sort of averaging as it could be. However,
are you sure about the nature of the signal? The reason I ask is,
when I view the output of the O2 sensor using my OBD-II reader at WOT,
the voltage will jump up to .92 to .96 volts (depending on the current
config of the truck) and will stay there until I let off the throttle
and the computer goes back into closed loop. If the O2 sensor signal
was an AC voltage, I would think that it wouldn't result in this
constant voltage readout. It is for this reason that I always just
assumed it was a DC voltage. Granted, I have not stuck a voltmeter
directly on the sensor during the WOT runs (only at idle) but I assumed
that the OBD-II software was giving me the direct sensor inputs.
Do you have any further information about this?
---Jon-
.---- Jon Steiger ------ jon@dakota-truck.net or jon@jonsteiger.com ------. | I'm the: AOPA, DoD, EAA, NMA, NRA, SPA, USUA. Rec & UL Pilot - SEL | | 70 Cuda, 90 Dak 'vert, 92 Ram 4x4, 96 Dak, 96 Intruder 1400, 96 FireFly | `------------------------------------------ http://www.jonsteiger.com ----'
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