[Shotimes] Re: Barometer sensor

[Kevin & Cheryl Airth]

Paul:
 They are very close but not quite identical.

The BP sensor is vented to the atmosphere while the MAP is connected to
intake manifold. That's why your BP sensor looks like it's missing a vacuum
hose.  It's the vent. The MTX SHO uses a BP. The ATX is kind of confusing
but the way I understand it is. The DPFE for the EGR feeds the BP readings
to the PCM. But they both measure pressure or vacuum as the case may be.
And some MAP sensors do measure BP during WOT and engine off periods. Since
in general most cars do not change altitude that fast or often, this works
pretty good. This sensor is used more at higher altitudes and cars operated
at or near sea level will often have no symptoms if this is bad. Hard to
diagnose too. Signal is a frequency and not voltage or resistance changes.
Ford does make a BP/MAP checker that converts the frequency to resistance so
you can check them with a regular DVOM. Swapping sensors is probably the
best troubleshooting technique.
.
.



> And is the MAP the same as the BARO sensor?
>
> Paul Nimz
> '97 TR
> '93 EG mtx
>

>
>   While trying to chase down my mysterious 2 digit codes on the '93, I see
a
> reference to the barometer sensor.  Is it the strangely, almost
rectangular
> shaped object in the middle of the firewall which has a 3 pin connector
> attached to it?  Is it suppose to have a vacuum line connected to it?
>
>   Helms says to see if it will hold 18" of vacuum to see if it is ok.
>
>   The part has the number E7EF-12A644-A2A on it.
>
>   Thanks
>
>   Paul Nimz
>   '97 TR
>   '93 EG mtx