Nightmare with Highlander 2015
I have exactly same issue and understand how frustrating and annoying the problem is. By experimenting in many ways, I know this doesn't have anything to do with AC, bluetooth, CD etc. Here is my painful journey so far:
4/17/2015: Bought 2015 Highlander LE Plus from Toyota North Brunswick (NJ) and noticed the buzzing sound after driving only ~30 minutes. The noise was becoming more frequent after driving ~ 1 hour. (120 miles on odometer) My Toyota sales guy says "observe for some time and go to service"
4/21/2015: Coming back from Philly to home (North Jersey), i.e. ~140 min of driving, it was happening about every other second. My sales guy wanted to check first.
4/24/2015: Sales guy came to my home to check early AM, but every time it happened he was using phone or said he didn't hear it. Also I noticed that the symptom wasn't frequent enough in the beginning of driving. So decided to go to service when it gets worse after driving a while.
4/28/2015: Coming back from Philly again, it was another crazy every other second noise. Went to Hackensack Toyota Service. Asked the receptionist not to turn off engine to show the symptom to service adviser, but he turned it off. So the service adviser couldn't hear it, but after driving a little bit, he heard it a few times. But the repair foreman was gone for the day.
4/29/2015: Went to service again to see foreman, he wanted to replace the whole multi media (audio) system to see if it has anything to do with audio system. He added he didn't know what else to do if new audio doesn't solve the problem. On the way home w/ new audio, I heard it again and again but kept telling myself it was from my ocd, not real. But later that night, while driving with my family and friend, every single one in the car said "how can you live with this crazy noise?". I realized that I was not hearing things. From this point, the noise became a major stress to me because I know I can't drive with this noise anymore unless I play music loud all the time.
4/30/2015: Back at service, service dpt manager wanted to test drive another brand new 2015 Highlander to see if this noise is normal or not. (1067 miles on odometer)
I left messages for GM at Toyota Brunswick, but no return call. I wanted to ask if GM has a remedy for this because this problem started from day 1, i.e. pre-existing condition. I wouldn't even talk to GM if this happened after owning the vehicle even a week.
This is my first Toyota, and I learned that even brand new cars can be a nightmare from day 1. I always buy new cars to minimize trips to repair shops, maybe I have been lucky so far cuz prior cars didn't develop any problems for at least several years.
The noise is driving me nuts. I just want to minimize this torture, so I will talk to lemon law lawyer if Toyota doesn't solve this problem soon. If no success w/ lemon law, I am even thinking about selling the vehicle away although it will be financially suicidal, cuz I don't want to lose my sanity. (1067 miles on car as of now)
My service manager will update me soon, I will update you as well.
The noise is almost like sleeping w/ 100 mosquitoes in the same room. If you guys have any update on this matter, please share your experience too. Thank you.
Sleepless in NJ.