How to check BOSCH MAP-Sensor (part no. 0 261 230 284) ? - Page 1
Forum section: electronics / repair

author: Greybeard
author_rank: Frequent Contributor
timestamp: October 30, 2024, 07:43:42 pm
content: 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: +5.0VPin32: GNDPin23: 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...

author: crerus75
author_rank: Contributor
timestamp: October 30, 2024, 07:53:49 pm
content: 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.

author: langwadt
author_rank: Super Contributor
timestamp: October 30, 2024, 08:39:01 pm
content: should be similar to thishttps://www.bosch-motorsport.com/content/downloads/Raceparts/Resources/pdf/Data%20Sheet_69416587_Pressure_Sensor_Air_PS-AA.pdf

author: Greybeard
author_rank: Frequent Contributor
timestamp: October 30, 2024, 10:38:28 pm
content: Quote from: crerus75 on October 30, 2024, 07:53:49 pmThat'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.

author: Greybeard
author_rank: Frequent Contributor
timestamp: October 30, 2024, 10:59:57 pm
content: Quote from: langwadt on October 30, 2024, 08:39:01 pmI think your PDF is spot on.The sensor shown in the datasheet has the exact same part number.The datasheet states a sensitivity of about4.0V/bar or1.8V/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 of0.4 or0.18V...It's much less what I expected, so I'll try to test again.BTW: How did you find that PDF?

author: langwadt
author_rank: Super Contributor
timestamp: October 30, 2024, 11:56:01 pm
content: Quote from: Greybeard on October 30, 2024, 10:59:57 pmI googled: bosch 0 261 230 284 datasheet

author: Greybeard
author_rank: Frequent Contributor
timestamp: October 31, 2024, 12:02:18 am
content: Quote from: langwadt on October 30, 2024, 11:56:01 pmHow could I have missed that?!

author: crerus75
author_rank: Contributor
timestamp: October 31, 2024, 03:54:37 pm
content: According to the data sheet, pin 3 is signal and pin 2 is ground. However, your original message states that pin 2 is signal (output) and pin 3 is ground. Please verify that you are measuring the correct pins and that you didn't accidentally reverse the two leads (or that Renault's wiring diagram is wrong).Where did you purchase this sensor? Unfortunately, both eBay and Amazon are somewhat notorious for selling counterfeit parts. They can look identical to the genuine ones, right down to date codes, boxes, logos, etc.

author: Greybeard
author_rank: Frequent Contributor
timestamp: October 31, 2024, 07:13:38 pm
content: Quote from: crerus75 on October 31, 2024, 03:54:37 pmThe pin function was assumed by me, I don't have Renault wiring diagrams.I will double check the pin numbers, thanks!Quote from: crerus75 on October 31, 2024, 03:54:37 pmI ordered the part from a German online spare parts dealer.It was claimed original from BOSCH and looks like original.

author: Greybeard
author_rank: Frequent Contributor
timestamp: November 01, 2024, 03:51:15 pm
content: Quote from: crerus75 on October 31, 2024, 03:54:37 pmThat's correct. Pin 3 is output.I measured 2.01V while engine running at idle.~2.3V at higher revs (~3000 RPM).1.93V at atmospheric pressure (sensor disconnected from intake manifold).So I think the sensor is working, I just confused pin numbers....(I edited pin assignment in my first post)

author: Greybeard
author_rank: Frequent Contributor
timestamp: November 01, 2024, 11:31:35 pm
content: I calculated the intake manifold pressures:@ idle:(2.01 V - 1.93 V) / 1.8 (V/bar) = 0.044 bar = 0.64 psi (positive pressure)@ ~3000 rpm:(2.3 V - 1.93 V) / 1.8 (V/bar) = 0.206 bar = 2.93 psi (positive pressure)Does that sound realistic for a turbo diesel engine?

author: crerus75
author_rank: Contributor
timestamp: December 02, 2024, 05:01:00 pm
content: Sorry for not getting back to you Greybeard, I just saw your reply.There are 2 ways to verify:1-- Hook a pressure/vacuum gauge up to the intake manifold and verify that what the sensor is reading is close to what the gauge is reporting.OR2-- Bench test the sensor. You can use a benchtop power supply or you can remove it from the intake manifold but leave it hooked up to the car's wiring harness. If hooked up to the car, turn the key on but do not start the engine. This should provide power to the sensor. You can then apply a known pressure or vacuum using a hand pump or similar and verify that the sensor output is close.Either method will work fine and it will probably boil down to whether a gauge is easier for you to obtain than a hand pump. Both are readily available on Amazon and other sources.Pressure/vacuum pump:https://www.amazon.de/-/en/Vacuum-Pressure-Tester-Bleeding-Device/dp/B08CRQ4QVF/ref=sr_1_2?crid=KV4CD9QDV94J&dib=eyJ2IjoiMSJ9.P7swDp1Anp9fxKor0DSn9NtVkltkcK7uyXZgmV3rY9YuslsON5ZTd4Lodl9dAlx8KJkwlrlidx7QidQe1cN5Vp6VHy8twcYxl7wdK6UFe0oEn3G_3R4dWLcDPKWaEQhbNJMVO3cxBdhMhajUkKj11KG5V-W-pB7rQL7VOdPFw-g6deJBMHvTH9pnu98isQiV5jZ2700qwrY1ejxthr83DY1-PgdlbHSxBXW8fnpz9lCXFBdti1B12KDJrq9ieXG4yl5OmREWecOyTK0uppVmtPgA7LdbYu3wZwWRQWO1TDc.aSDydFS0_kk07wkwdqmQiglN3mx4y9ffmlYafKkdlCk&dib_tag=se&keywords=pressure+vacuum+gauge&nsdOptOutParam=true&qid=1733158622&sprefix=pressure+vacuum+gauge%2Caps%2C151&sr=8-2Pressure/vacuum gauge:https://www.amazon.de/-/en/MRCARTOOL-Carburetor-Automatic-Pressure-Diagnostic/dp/B08HCXLT94/ref=sr_1_5?crid=KV4CD9QDV94J&dib=eyJ2IjoiMSJ9.P7swDp1Anp9fxKor0DSn9NtVkltkcK7uyXZgmV3rY9YuslsON5ZTd4Lodl9dAlx8KJkwlrlidx7QidQe1cN5Vp6VHy8twcYxl7wdK6UFe0oEn3G_3R4dWLcDPKWaEQhbNJMVO3cxBdhMhajUkKj11KG5V-W-pB7rQL7VOdPFw-g6deJBMHvTH9pnu98isQiV5jZ2700qwrY1ejxthr83DY1-PgdlbHSxBXW8fnpz9lCXFBdti1B12KDJrq9ieXG4yl5OmREWecOyTK0uppVmtPgA7LdbYu3wZwWRQWO1TDc.aSDydFS0_kk07wkwdqmQiglN3mx4y9ffmlYafKkdlCk&dib_tag=se&keywords=pressure+vacuum+gauge&nsdOptOutParam=true&qid=1733158622&sprefix=pressure+vacuum+gauge%2Caps%2C151&sr=8-5Note that the gauge only goes up to 10PSI (less than 1 BAR), so be careful when testing anything with positive manifold pressure (IE a turbocharger in your case).If you're still diagnosing this, please let us know what you find.