little_idiot

Hi all,

as i've just picked up my new MAF sensor from the dealer, i can see that it must be the piece of wire that is the sensor bit.

what i want to know though, is how it actually works. so any techy's, as much detail as you like as i'd like to think that i can understand most things if explained!

James

TonyFlow

Wire heats up to a set temperature- air cools wire down, car takes voltage reading of what is required to keep wire at said temperature.

little_idiot

that'll do for me!

didn't realise it worked on a temperature basis. won't that provide problems on a daily basis as the air temperature and ambient temperatures change?

grahamfrary

I guess so in theory, but the wire is pretty hot ie much hotter than ambient, and the cooling effect will be proportional to the temperature difference, so changes in ambient shold have much effect.

Bendalyn

built into the maf sensor there is usually a ACT (air charge temperature) sensor. The PCM uses this information to compensate the daily changes in air temp. Comparisons are made in software with the AAT (ambient air temp) sensor as there will probably be upheat of the charge temp as it passes through the air cleaner and resonators - especially on hot days and in traffic when there isn't much airflow over the car and not much air passing through the air intake system.

little_idiot

cheers guys, all makes sense now


James