Only the XM input is playing louder on the left, siginificantly so. The right is still there, but barely. Every other input is working normal (CD, Tuner, iPod, BT audio) so it's not my external amp. Could it be the XM tuner unit? Anyone have this problem?

Could it be just that input is wearing out? Will probably just try another XM tuner, but since they are still $90 just trying to see if there's a 'simple fix,' since my unit is not easy to get to.

Thanks!

well it could be either a problem with the XM tuner not outputting the signal correctly, the IPbus cable restricting the signal from the XM tuner, or the IPbus input on the avic could be bad.