Would a BAP sensor fail a MAP test???

SCollord90

Registered User
Well as you all know I'm a genius! So being the smart guy that I am and trying to get my A/F ratio fixed. I went to autozone and tested my BAP sensor thinking it was a MAP sensor. It failed so I bought a new MAP sensor (which was listed for my car in their computer).

So my question is: Would my BAP sensor fail the MAP sensor testing? We used a power supply, voltmeter, and a vacuum pump to test it. Do I need a new BAP still? :confused:
 
SCollord90 said:
Well as you all know I'm a genius! So being the smart guy that I am and trying to get my A/F ratio fixed. I went to autozone and tested my BAP sensor thinking it was a MAP sensor. It failed so I bought a new MAP sensor (which was listed for my car in their computer).

So my question is: Would my BAP sensor fail the MAP sensor testing? We used a power supply, voltmeter, and a vacuum pump to test it. Do I need a new BAP still? :confused:

And uhhh, what did the voltmeter indicate? Something like 2.5vdc I'll bet. :)

See, the MAP/BARO's signal can be displayed as a frequency, or as a square wave on an oscilloscope since it's a digital signal.

As a frequency it should be about 160Hz at ambient pressure, and about 106Hz at 20inHg.
 
Somebody punch me please!

Oops, I guess I shouldn't type just before leaving for work. The main reason I say that it failed the test is because with constant pressure, I believe it was changing readings. So I guess I just answered my own question by rethinking . Because no matter what it is it should have a consistant reading with a constant pressure. ( I need a little idiot face to put here)
 
SCollord90 said:
We used a power supply, voltmeter, and a vacuum pump to test it.

This is NOT the way to properly test a Ford MAP/BAP sensor. The voltage output is (almost) irrelevant. Obviously that guy at Autozone has no idea how they work... :rolleyes:

SCollord90 said:
Because no matter what it is it should have a consistant reading with a constant pressure.

No, this is a false conclusion. The reason the readings were fluctuating is because he was trying to measure an AC voltage on the DC setting.

Parker Dean said:
See, the MAP/BARO's signal can be displayed as a frequency, or as a square wave on an oscilloscope since it's a digital signal.

Correct (except I would change "can be displayed" to "must be measured"). The output is a frequency based signal, and the frequency changes with changing pressure. The easiest way to test them is with a frequency counter, however an oscilloscope will do nicely if you have one (this also allows you to look at the waveform pattern at the same time to see if it's possibly mis-shapen or 'dirty').
 
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