ECU

[rizov_d at shaw.ca]

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In case when there are:



-     No fluctuations of control pressure actuator current (steady at 17.7 mA)

-         No preset values in open-loop (~10 mA)

-         No ability to enrich (when ground the OXS probe wire), but only to
enlean with small battery voltage (+)



Could be a conclusion drawn that ECU is faulty?



Any experience repairing ECU?



What could be a reasonable price for an used ECU?



Thx,



Dobby







----- Original Message -----

From: Huw Powell <human747 at attbi.com>

Date: Monday, January 6, 2003 12:54 pm

Subject: Re: ECU

>
> > CIS-E,
> >
> > When in open loop does the ECU gets in preset values for
> differential pressure
> > regulator (8-10 mA) , with no fluctuations?
>
> Yes, basically. In open loop the current is fixed by the ecu -
> when the
> engine is cold, it is higher than that, though, to provide enrichment.
> When the WOT switch is closed it is also in open loop, with a slight
> enrichment to help you accelerate.
>
> Perhaps there is also a default for warm engine and no OXS signal, but
> there might not be, since that is not a "normal" operating condition.
>
> The fluctuation in closed loop is due to the ECU constantly adjusting
> the mixture slightly in response to the OXS signal, so the engine is
> always veering a tiny tiny bit rich or lean - but very close to
> perfectmixture.
>
> The later CIS E3 cars fluctuate around 0 mA, so in the case of no
> powerto the ECU, they are capable of limping along ok - though not
> very good
> at starting when cold.
>
> You might want to do some searching of the archives, as I'm sure at
> times myself and others have written detailed explanations of how
> CIS-lambda systems work; there is also my web site which might be
> helpful.
>
> --
> Huw Powell
>
> http://www.humanspeakers.com/audi
>
> http://www.humanthoughts.org/
>