[DJ_Playing]

Recently my 09 has started periodically producing a loud hum (like a blown speaker/amp) shortly after you start it. its slowly getting worst. It sounds like an amp problem but it can happen with or without the radio on. There is a box under the drivers seat and that is where it feels like its coming from.

Is this a know issues / common problem?

 

[Jo e Lefors]

First let me welcome you to the forum from Las Vegas Nevada.
Now for your question.
Yes it is a common and known problem.
It is most likely the subwoofer.
The subwoofer can be unplugged and the noise will stop. There are post with pictures if you do a search for subwoofer.
Briefly, sitting in the driver's seat with it slid all the way back. There is a plug on your right side at the front of the seat frame. Pull that plug and no more noise.
Please try doing the search first I posted some good pictures.

Good luck & take care.

JL

 

[Jo e Lefors]

Recently my 09 has started periodically producing a loud hum (like a blown speaker/amp) shortly after you start it. its slowly getting worse. It sounds like an amp problem but it can happen with or without the radio on. There is a box under the driver's seat and that is where it feels like its coming from.

Is this a know issues / common problem?

Checkout post number 18 with picture.
https://www.smartcarofamerica.com/f...ivers-seat-flood-car-update-54538/index2.html

 

[BB Benz]

If you decide to replace the subwoofer, the seat bolts bolt through it. Disconnect your battery for a little while before disconnecting the cables going to the airbag in the seat. Take the seat out without disconnecting the seat belt from the seat. It will reach. You then have full access to the subwoofer.
Remember to leave the battery disconnected the entire time the seats are disconnected from their cables, or you will need a Star machine to reset the OBD code that is lighting the SRS light and disabling your air bags. The dealer is very willing to charge for that service. After all, you did not bring said defective machine to them for service, therefore you will be punished with a service fine.