If you have first confirmed 100% you have wired it correctly, check this out. A customer sent this to us:
Just wanted to give a follow up on this for your reference for future support cases.
Sound continues to work on my unit following a hard reset by disconnecting the battery for an extended period of time. I now believe that this issue is caused by the Lexus Safety Connect telematics service. It can deliver a mute signal to the amplifier via the DCM (Data Communication Module). I believe this is what was causing my sound issue. Interestingly, I remember seeing that sound was muted on the car side in the Hamilton menu which is likely an indicator. There is an interesting thread on clublexus about the issue.
https://www.clublexus.com/forums/nx-1st-gen-2015-2021/999870-radio-turns-on-but-no-sound.html
Anyways, it has nothing to do with your unit, but I thought I would share it with you in case any of your future customers encounter the same sound issue.
Bottom line the Lexus Safety Connect Telematics system can glitch overriding system audio. This is cured by an extended battery disconnect (couple of hours). Very very rare.
