U0164 Error code

Originally Posted by Nism0

My friends car now has no communication to the HVAC controls, heated seats, cruise control, home link mirror, and outside temp reading is way off.

We tried swapping out the white box under the radio. We tried swapping out the face plate to the head unit. He installed a new rely behind the navi. He also changed all the 25 and 10 amp fuses in the fuse box under the steering wheel and both boxes in the engine bay. He did find some blown fuses in the engine bay boxes.


We are totally lost at this point. What could we be missing??