# I.8T conversion... Barometric pressure sensor (BARO) question



## vw2porsche (May 4, 2002)

Did a 1.8t conversion on a Corrado. Car runs rough at higher RPMs and has lousy fuel mileage (11.5 mpg highway







). Got a code that says barometric pressure sensor (BARO) signal is too high. After looking at the electronic schematics for the Audi AEB computer then the physical wire harness I realize the sensor is not there. In a stock application it's in the same plastic enclosure as the ECU.
Can someone tell me how the computer uses this sensor and not having one might effect the engine?


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## Veedubgti (Mar 5, 2001)

*Re: I.8T conversion... Barometric pressure sensor (BARO) question (vw2porsche)*

Don't know much about the BARO sensor, but IIRC it tells the ECU how much boost to request via N75 valve based on how thin the air is at that given time. No idea how it affects running, I've always had mine plugged in.


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## moneymakin (Sep 14, 2003)

*Re: I.8T conversion... Barometric pressure sensor (BARO) question (vw2porsche)*

It has an effect on the fuel mixture, why don't you install it??
ryan


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## vw2porsche (May 4, 2002)

*Re: I.8T conversion... Barometric pressure sensor (moneymakin)*

I'm already on it, when I got the computer and wire harness it was'nt there. I wanted to get an understanding of it's function and how it would relate to the problems I'm having.


_Modified by vw2porsche at 6:21 PM 6-10-2004_


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## punkassjim (Sep 22, 2002)

*Re: I.8T conversion... Barometric pressure sensor (vw2porsche)*

I'm not entirely sure on its function either, but my barometric pressure sensor was an external unit on my mk3 wiring harness (ABA) AND my 1.8T wiring harness (AWW). Not sure why it would be different for the AEB vehicles.
It just looks like a little geiger counter...in fact, if you still have the wiring harness from the Corrado, your old one might work with the AEB harness. Look for an empty plug up near where your ECU is, or up around the rain tray.


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## 76 Golf GTi (Aug 24, 2001)

*Re: I.8T conversion... Barometric pressure sensor (punkassjim)*

Bumpity for an update-ity.


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## mattinbend (Oct 12, 2000)

*Re: I.8T conversion... Barometric pressure sensor (76 Golf GTi)*

Well since the AEB has no MAP sensor I think the BP sensor works in tandem with the maf and air intake temp sensor to calcualte manifold pressure.


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## 76 Golf GTi (Aug 24, 2001)

*Re: I.8T conversion... Barometric pressure sensor (mattinbend)*

Stupid question: So if I don't have a MAP sensor on my AEB then I can't do the diode mod, correct?


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## motorlager (Sep 26, 2005)

*Re: I.8T conversion... Barometric pressure sensor (mattinbend)*


_Quote, originally posted by *mattinbend* »_Well since the AEB has no MAP sensor I think the BP sensor works in tandem with the maf and air intake temp sensor to calcualte manifold pressure.

Thats right
here's what it looks like


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