so im wanting to convert an me7.1.1 car to a hitachi maf.
my notes:



w8 bosch ecu/maf pin:
26 / 1 / yellow / iat sensor wire
d22 / 2 / green/yellow / +12v
27 / 3 / green / connects to brake boost pressure / ground
53 / 4 / lilac/yellow / +5v
29 / 5 / black / signal

s4 hitachi ecu/maf pin:
53 / 1 / lilac/gray / +5v
? / 2 / green/yellow / +12v
27 / 3 / black/green / ground
29 / 4 / green / signal

s4 bosch ecu/maf pin:
g235 / 2 / green/yellow / +12v
27 / 3 / black/green / ground
53 / 4 / lilac/gray / +5v
29 / 5 / green <- black connects @ 200 (ground connection shielding) / signal

so since the ecu pin #'s seem to match up pretty well, this is what i figured:

hitach maf pin / color      w8 color / purpose:
1 / lilac/gray        lilac/yellow / +5v
2 / green/yellow             green/yellow / +12v
3 / black/green        green / ground
4 / green                black / signal

my only really concerns were a) do my notes look correct? and b) why is there a 5th (yellow) wire on the original 7.1.1 maf?
EDITED TO ADD IAT WIRE NOTE.

how does that look like the extra wire? did you read all 3 pinouts? there are 3 ecu pins common to all maf's. 27, 29, 53, and a 12v power wire connected not from ecu.
i patched hitachi maps from an s4 file as a starting point.

well, just in case anyone ever references this, the wiring is 100% correct. also, adding a 5th pin to the stock hitachi maf connector and connecting it to the yellow (extra) wire in the harness gives a working iat sensor.

you know to be honest i didnt even really think about that.
thats a good point. ill pay more attention the next time im at the car. really i was just more excited that it was all working.