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Atmospheric Pressure Sensor?

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Old 04-13-04, 05:33 PM
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Atmospheric Pressure Sensor?

I tested my ecu for problems and it came up with a code from the APS (1 long-4 short) I tested it and the voltage going across is close to .9v when it supposed to be much higher 3.5-4.5v... Any ideas what might be wrong or do I have to go replace the POS.
How important are the readings comming out of the APS? I fixed the waterthermosensor and it starts fine now...(knock on wood)
Old 04-13-04, 05:40 PM
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are you reading the voltage "going across" it, or the voltage OUTPUT (black lead on a good ground) to the ECU?
Old 04-14-04, 06:42 AM
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pin D on the APS has .9v comming out of it...Thats comming directly out of the plug attached to the APS...

I'm looking for the wrong voltage in the wrong places arent I?
Old 04-14-04, 07:28 AM
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I'm confused - Are you refering to the "pressure sensor" at the right strut tower or the "atmospheric pressure sensor" INSIDE the ECU?
Old 04-14-04, 07:57 AM
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the APS is inside the ECU?
In the haynes manual when they tested the APS it shows it on the strut tower but maybe Im looking at the pic wrong...

All Im sure of is that my check lights are comming up with code (1 long-4 short) which is the APS right?
can I drive it for short distances just to break in the engine or will it hurt?
Old 04-14-04, 09:05 AM
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The sensor on the right strut tower is the "boost sensor." The APS is located inside the car on the passenger side under the dash.
Old 04-14-04, 09:33 AM
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Originally posted by Crionics
The sensor on the right strut tower is the "boost sensor." The APS is located inside the car on the passenger side under the dash.
My bad on the "inside the ECU" error

On the strut tower:
NA = boost sensor
TII = pressure sensor
(mumbles something about Japanese translation - go figure)
Old 04-14-04, 09:49 AM
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Originally posted by SureShot
My bad on the "inside the ECU" error

On the strut tower:
NA = boost sensor
TII = pressure sensor
(mumbles something about Japanese translation - go figure)
Ah ya, good call. I don't know if they are different sensors, or if they just decided to amke things difficult.
Old 04-14-04, 12:17 PM
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The Green/Yellow wire coming out of the Atmospheric Pressure Sensor should read the FSM voltages. I THINK the last time I looked it was maybe 3.8 or so.

If broken or the plug is removed, the ECU defaults the sensor to sea level atmosphere pressure. I'd replace it if it isn't close to the factory figures. What height above sea level are you at, by the way. The .9v is no good.
Old 04-14-04, 02:59 PM
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I live right off the ocean... at most I might be 800 ft above sea level. is it beside the ECU?
Old 04-14-04, 04:07 PM
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****is it beside the ECU?*****

The location?????? It's located about a foot above the ECU and to the right. Towards where the harness comes through the engine bay. Over that a way.

Your ECU does have the numbers N332 on it , does it not?

Back probe the ECU middle connector. Pin 2H. All connectors connected up and the key to ON or even running if you wish. Won't make a diff..

Maybe unbolt the ECU where you can tilt it up to get at the pin easier. Should be the color described in the other post.
Old 04-14-04, 04:14 PM
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doesn't matter if you're near the ocean or not...you could read 3v one day while it's storming outside, and 4.5 v the next day with a high pressure weather system over ya...it's basically a barometric pressure sensor- not an altimeter! Did ya follow Hailer's advice and read a voltage output at the ECU pin?(other probe on a good ground near the ECU)
Old 04-14-04, 05:31 PM
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That .9 volts is somewhere in the statosphere.

The guy in Denver Colorado will see closer to 2.5 than 3.5 and at sealevel you'll not be seeing anything under 3.5 for sure.
Old 04-15-04, 07:22 PM
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well I checked the APS comming out of the ECU and its comming up at 0...

where is the aps located exactally and what does it look like? In the haynes manual they have it by the front strut tower
Old 04-15-04, 08:20 PM
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now you're talking about the boost/ pressure sensor AGAIN!!! BTW, the APS voltage doesn't come "out" of the ECU, it goes "into" it (the output voltage of the APS is the same thing as the input voltage to the ECU- there's only a wire between the two...if you pulled back the carpet & got to the ECU, your right elbow will be damn near hitting the APS- it's RIGHT THERE

Last edited by WAYNE88N/A; 04-15-04 at 08:25 PM.
Old 04-16-04, 02:38 PM
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no I NOW know that the one by the strut tower is the pressure sensor... Im just saying in the manual it dosent show what it looks like, but I know its close above the ecu and to the right.. what does it look like?
Old 04-17-04, 07:45 AM
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It looks almost identical to the Boost/pressure sensor in the engine bay.

It is black in color.

It has one electrical plug, no nipple

The kick panel needs to be removed to see it.

If you measure from the center of the heater fan motor, the distance is seven inches in a diagonal direction to the right. It's about the same height as the BOTTOM of the heater/fan motor. It has a four pin plug, if I remember right.
Old 04-17-04, 04:18 PM
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well you are precise.
thanks AGAIN Hailers!
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