I appreciate the feedback guys. I am going to do just that. It was a Toyota dealership and so I think I am going to take it back to them. Thank you for the input, I'll get that done this weekend and I will update you guys.
Did you ever find out what the problem was? I am having a similar issue with my front speakers, but I DO NOT have JBL system.. and where the amp looks to be in JBL systems, I have empty storage.
When we test my front speakers they arent even getting power from the HU (new pioneer avh-x2800bs). It is like they are bypassing to another amp located somewhere.
2007 4Runner SR5 v6