I have an 04 TL with Navi. I noticed that there wan't as much base as usual and when to adjust the subwoofer on the Navi screen, and it stays in the "off" position. It will not increase with any touch etc. Is there a specific relay for the sub which may be blown or am I missing something obvious?
Thanks...

 

there could me numerous problems, the HU itself, the amp or the sub itself. Take it to your dealer to have them diagnose the location, because that HU is over 500 dollars.