Hi does anybody know what the Green/Brown wire is for on the mass air flow sensor? Thanks
2005 XJR...

 

-ve signal to ECM for IATS.

 

Do you happen to know what the rest are for? I looked at the electrical diagrams by I don't understand what the U, BK, GU, U, Etc mean

 

They don't really mean anything. They are just the wire colours so they can be physically traced. Just trace them back to the ECM on the wiring diagram to see what they do. -ve in triangle is a common signal ground by the ECM. "I" in triangle is signal output from sensor to ECM. I believe any number in a circle is always to a switched +ve line.

 

OK for instance what would U be for a color. Is there a description somewhere in there I'm not seeing...Thanks!

 

Wiring Color Codes
N Brown O Orange
B Black S Slate
W White L Light
K Pink U Blue
G Green P Purple
R Red BRD Braid
Y Yellow BOF Black fiber optic (D2B Network)

 

Awesome now that was what I was looking for it all makes sense now! Thanks