CEL On U0164
 

So after i installed headers/downpipes/exhaust on my 370z everything was fine for around 2 weeks... i then saw the CEL come on and about 3 days later went away... it did this a few times for next month then was off for a while... however last week it came on and stayed on and i checked the code and this was what i got

U0164 Generic DTC: Lost Communication With HVAC Control Module

and my AC also does not seem to work so my question to you is will nissan void this since i did header work and what not?

very nervous to take this in

looks like something is unplugged to me. Have you checked all the connections?

i was looking all around i couldnt find anything i will put car back up on stands and see what i can find.

"U" codes are CAN network related codes, either no connection or no communitaction between moduels. Either something is unplugged or there is an open in the circuit somewhere.

CAN wires are a pair of wires wrapped around each other; hope that helps

so i thought of something i had a bluetooth ODBII device that was kinda lose in there... i pulled it but it didnt go away right away thought about resetting by pulling battery to see

Friend having similar problem. OP, did you ever solve the issue?