cyotani

iTrader: (8)

Hi, I am trying to use a spare 1.8 MAF sensor I have in my garage for my Mechanical Engineering controls project. I can not find a wiring diagram to find the pin out for the sensor. Does anyone know the pins?

Were using it to create a PID feedback controller for a dynometer fan for my School's FSAE team

Joe Perez

iTrader: (8)

Pinout varies by year.

For '94-97, wherein the IAT sensor is integrated into the MAF assembly:



Wherein:

W/R = 12v
R/B = IAT
R/W = MAF (0-5v)
B/L = signal ground
B/LG = power ground






For '99-'05:



Wherein:

W/R = 12v
LG/B = MAF (0-5v)
B/L = ground

cyotani

iTrader: (8)

https://www.miataturbo.net/megasquir...n-14166/page5/

I found this thread and put 12V to pin 5 and grounded pin 1 and used a DMM to read the voltage between 2 and 4 but am getting 0 volts.

Joe Perez

iTrader: (8)

Re: the thread you linked to- know that there was a lot of misinformation floating around back then.

Re: your most recent test: Did you expect something other than 0v at the output with no airflow? (While the mechanical airflow meter in the '90-'93 cars scaled from 5v = no airflow to 0v = maximum airflow, rest assured that the hotwire MAF sensors in the '94-'05 cars scale "properly," wherein 0v = no airflow and 5v = maximum airflow.)

cyotani

iTrader: (8)

Thanks for the help Joe!

I have a household fan and am measuring voltage with it off and with it blowing full blast into the MAF. I think that should be enough airflow to get a reading on my DMM but nada

cyotani

iTrader: (8)

This is how I have it wired at the moment. red alligator is +11.55 from a battery and yellow is the battery negative terminal. 2nd pin from left is DMM ground and 4th from the left is DMM positive. (I made sure I have clean connections to the pin without the two adjacent alligator clips touching). Still no voltage regardless of airflow.

cyotani

iTrader: (8)

This says far left is ecu ground (signal ground). but either way I still get 0 V regardless of airflow.

How to Test a 1995 Mazda Miata Mass Air Flow Sensor | eHow



Nice write up by the way Joe!

AFM Removal from the 1.6 liter Miata using eManage Ultimate

Joe Perez

iTrader: (8)

Just a quick note as I hop on the train- you should probably ground both MAF grounds to the same point, and take your measurement relative to that combined ground.

cyotani

iTrader: (8)

Okay, so the sensor ground and power ground should both go to the negative battery terminal and use a DMM to find the voltage from common ground to the sensor output 0-5V?

Joe Perez

iTrader: (8)

That's the idea.

cyotani

iTrader: (8)

Worked like a charm! Thank you for the help good sir!

Electronic circuits is not my strong point. But now that I think about it common ground makes sense. I should known that one. Now on the PID portion. Should be a fun project.

Joe Perez

iTrader: (8)

All that is visible must grow beyond itself, and extend into the realm of the invisible.