Afm Voltage

[RPR33]

Hey guys

Where do I put the voltage reader to check afm voltage? and should this be done on a dyno to check it under load and at different rpm range?

Cheers

[InterCooL]

i'm guessing pin 27

http://wiki.r31skylineclub.com/images/7/72...ECU_Pinouts.jpg

it will get to max volts at max rpm under load

on a flat road mine maxes out in second and third gear. but i was able to check using data logging software, i guess you'd need a quick response multimeter and a friend looking at it

it could be easier to do it on a dyno. but not cheaper

Edited April 10, 2008 by InterCooL

[QWK32]

yeah. probe into the afm signal in wire on the ecu with a multimeter. you dont need a quick response multimeter, just put it in the gear you want and put you foot down, it helps if you have a peak hold feature on your multimeter. what are you looking for? just checking to see if your afm is maxing out. they are 0-5v reading. but usually anything after 4.5v is maxed out.

and yes, you should do this under load to get a reading.

[**RB2530**]

Most nissan afms will have output of 0-6ish volts. They do this as the ECU will register up to 5.12V exactly ...this is the limit of the A-D converter in the ECU..To detect 'maxing out' you really need to log the afm voltage vs time or if you measure an afm voltage of 5.12v you are on the limit..

[RPR33]

thanks guys. the car has been playing up a little, (pinging as it comes on boost). so i changed a few things and one thing that seemed to help was putting in another afm. with the other afm in it seems to run fine. so I'm just trying to figure out what is wrong with mine and, if it can be fixed or if I should just replace it.

[QWK32]

you could try cleaning the afm. just get some contact cleaner and give the probe a good spray. if its still playing up after that i'd open it up and resolder the joints, it a common problem with afm's to have dry joints. have a look in the tutorial section, there is a write up in there about how to do it. and if that doesn't work its time for a new afm.