Reported O2 volts

[nacelp]

> > Reading a '91 Cavalier shop manual, it says that the ECM supplies .450
> > volts on the 02 sensor wire; this contradicts everything I've read since
I
> > thought you NEVER apply any voltage [even current limited] to the 02....

??, Why not?, the O2 generates a voltage and applies one.
I've applied voltages to them for years, basically.  Just I haven't tried
over 1 volt.

> Yes, the ECM applies a tiny bit of current to the O2 sensor.  The
> NatSemi LM9044 O2 amp typically applies 380 nanoAmps to the O2 signal
> wire.  The O2 ground wire typically gets 65 microAmps.

On the one ecm (1227749), I got rigged at the moment the supplied voltage to
the O2 is .390 volts, with a reported by diacom .45v engine on not running,
then when the ecm thinks the engine is running (or not) follows the O2
voltage fairly closely.
Grumpy


> Ludis Langens                               ludis (at) cruzers (dot) com
> Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/


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