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How to check BOSCH MAP-Sensor (part no. 0 261 230 284) ?
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Greybeard:
I need a little help to check the function of this MAP sensor (manifold absolute pressure sensor).
It is part of the Renault Laguna II 1.9L dCI diesel engine.

I already checked:
Pin 1: +5.0V
Pin 3 2: GND
Pin 2 3: Output? (~0V) 
EDIT: (corrected PIN assignment)

I checked the voltage at pin 2, it doesn't change while driving or when pulling the sensor out of the manifold.
I also applied the 5V supply voltage from a laboratory power supply. Pin 2 does not react on pressure changes, voltage stays near GND, no pulses visable at oscilloscope.
BOSCH doesn't send me a datasheet. Maybe the function of this "high-tech" part is top secret...

crerus75:
Most 3-wire MAP sensors will output an analog voltage proportional to the amount of pressure in the intake manifold.  They typically act as analog pressure transducers.  I'm not aware of any that produce pulses or variable frequencies, but perhaps they exist.

A quick search on Google lists this as a boost sensor, which would make sense for a diesel engine.  Try bench testing the sensor by applying power and then blowing into the inlet.  You should see something on the output pin.  If neither pressure nor vacuum causes the output on pin 2 to change, I'd say you have a dead sensor. 
langwadt:
should be similar to this https://www.bosch-motorsport.com/content/downloads/Raceparts/Resources/pdf/Data%20Sheet_69416587_Pressure_Sensor_Air_PS-AA.pdf
Greybeard:

--- Quote from: crerus75 on October 30, 2024, 07:53:49 pm ---Most 3-wire MAP sensors will output an analog voltage proportional to the amount of pressure in the intake manifold.  They typically act as analog pressure transducers.  I'm not aware of any that produce pulses or variable frequencies, but perhaps they exist.

A quick search on Google lists this as a boost sensor, which would make sense for a diesel engine.  Try bench testing the sensor by applying power and then blowing into the inlet.  You should see something on the output pin.  If neither pressure nor vacuum causes the output on pin 2 to change, I'd say you have a dead sensor.

--- End quote ---
That's exactly what I did before, but the output voltage remained almost constant (PS: or the voltage change was much smaller than what I expected, see my next post).
So I thought the output might be digitally encoded pulses, but my oscilloscope couldn't detect any pulses.
This sensor is a new replacement part, but the original one from the car doesn't respond either.

Greybeard:

--- Quote from: langwadt on October 30, 2024, 08:39:01 pm ---should be similar to this https://www.bosch-motorsport.com/content/downloads/Raceparts/Resources/pdf/Data%20Sheet_69416587_Pressure_Sensor_Air_PS-AA.pdf

--- End quote ---
I think your PDF is spot on.
The sensor shown in the datasheet has the exact same part number. :-+

The datasheet states a sensitivity of about 4.0V/bar or 1.8V/bar (0.2 to 2.5 bar sensor), output voltage range 0.4-4.65V.
I don't know what pressure I could generate with my lung for the "bench test", maybe 1/10 bar.
So I should see a change of 0.4 or 0.18V...
It's much less what I expected, so I'll try to test again.

BTW: How did you find that PDF?
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