ECU value for O2 Sensor

My understanding is that if your O2 sensor fails, the ECU replaces the
values it should receive from it (0-1v) with a default value. My question
is, what is the value the ECU uses?

On Sat, 7 May 2005 14:56:00 +1200, "Steve Gibbs"
> wrote:

>My understanding is that if your O2 sensor fails, the ECU replaces the
>values it should receive from it (0-1v) with a default value.

No, it doesn't.

> My question
>is, what is the value the ECU uses?
>
see above.

Steve Gibbs wrote:

> My understanding is that if your O2 sensor fails, the ECU replaces the
> values it should receive from it (0-1v) with a default value. My question
> is, what is the value the ECU uses?
>
>
loop
break the loop and what happens?

magic

Steve Gibbs wrote:
>
> My understanding is that if your O2 sensor fails, the ECU replaces the
> values it should receive from it (0-1v) with a default value. My question
> is, what is the value the ECU uses?

The question is way, way more complicated than that.
Essentially, and it varies from car to car, the ECU
look up on a table how much fuel to deliver based on
various sensor readings such as MAP, MAF, coolant temp,
etc, then it provides that amount of fuel. Then it looks
at the O2 sensor to see if the mixture ended up being too
rich or to lean, adjusts the mixture for that particular
set of sensor readings, and repeats. Most ECUs have a series
of settings stored so that the car can run in "limp home"
mode, those settings are on rather large lookup tables.

JazzMan
--
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Do you have a code for o2 sensor failure?
"JazzMan" > wrote in message
...
> Steve Gibbs wrote:
>>
>> My understanding is that if your O2 sensor fails, the ECU replaces the
>> values it should receive from it (0-1v) with a default value. My
>> question
>> is, what is the value the ECU uses?
>
> The question is way, way more complicated than that.
> Essentially, and it varies from car to car, the ECU
> look up on a table how much fuel to deliver based on
> various sensor readings such as MAP, MAF, coolant temp,
> etc, then it provides that amount of fuel. Then it looks
> at the O2 sensor to see if the mixture ended up being too
> rich or to lean, adjusts the mixture for that particular
> set of sensor readings, and repeats. Most ECUs have a series
> of settings stored so that the car can run in "limp home"
> mode, those settings are on rather large lookup tables.
>
> JazzMan
> --
> ************************************************** ********
> Please reply to jsavage"at"airmail.net.
> Curse those darned bulk e-mailers!
> ************************************************** ********
> "Rats and roaches live by competition under the laws of
> supply and demand. It is the privilege of human beings to
> live under the laws of justice and mercy." - Wendell Berry
> ************************************************** ********
>



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In article >,
Lawrence Glickman > wrote:

> On Sat, 7 May 2005 14:56:00 +1200, "Steve Gibbs"
> > wrote:
>
> >My understanding is that if your O2 sensor fails, the ECU replaces the
> >values it should receive from it (0-1v) with a default value.
>
> No, it doesn't.

Actually, it depends on the vehicle.
Some do, some don't.

> > My question
> >is, what is the value the ECU uses?
> >
> see above.

I've seen anywhere from .44 volts up to 10 volts.

On Sat, 07 May 2005 13:06:00 GMT, aarcuda69062
> wrote:

>In article >,
> Lawrence Glickman > wrote:
>
>> On Sat, 7 May 2005 14:56:00 +1200, "Steve Gibbs"
>> > wrote:
>>
>> >My understanding is that if your O2 sensor fails, the ECU replaces the
>> >values it should receive from it (0-1v) with a default value.
>>
>> No, it doesn't.
>
>Actually, it depends on the vehicle.
>Some do, some don't.
>
>> > My question
>> >is, what is the value the ECU uses?
>> >
>> see above.
>
>I've seen anywhere from .44 volts up to 10 volts.

Learned something *new*

Lg