O2 sensor

[David A. Cooley]

Closed loop depends on more than the O2 sensor activity... it depends on
time since start on some models, coolant temp, throttle position AND O2
sensor activity.  When the O2 sensor is hot, it should be bouncing from
lean to rich (low V to High V) several times a second... At idle it should
be sending a voltage (But it can ONLY be monitored by a Digital meter with
several Meg-Ohms per volt input impedance...an analog meter across it will
ruin it!)


At 08:23 PM 3/14/99 -0700, you wrote:
>I have a question about how to tell when the computer is in closed 
>loop mode when a person doesn't have a scan tool.
>I built one of the O2 sensor gauges using the LM3914 chip.  What 
>should I be looking for to tell when closed loop is on?  From what I 
>have read, I should see the gauge fluctuating several times a 
>second (or as close as the eye can tell).  Also, with the O2 sensor 
>disconnected from the computer, the O2 sensor does not send a 
>voltage during idle even though it is a heated sensor.  I find this 
>interesting.  

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           David Cooley N5XMT           Internet: N5XMT at bellsouth.net
     Packet: N5XMT at KQ4LO.#INT.NC.USA.NA   T.A.P.R. Member #7068
       I am Pentium of Borg...division is futile...you will be approximated.
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