F83 Convertible Disable Active Sound

[bmoss1610]

I took delivery of my F83 M4 convertible a couple of weeks ago. I got mine with a port installed M Performance Exhaust. I love the exaust but the Actve Sound Design (“ASD”) fake exhaust sound in the cabin was driving me crazy. In my view, it’s cheesy under any circustances, but with the M Performance Exhaust it creates a very annoying drone and it competes so the driver can’t properly hear the true sound of a very expensive and very well designed exhaust system. I looked at a bunch of posts and debated whether to ask my dealer to de-program ASD or just find the module and pull the plug. The positioning and access in the convertible is a little different than in the coupe (it’s actually a bit easier), and I couldn’t find any convertible specific DIY posts, so I created this one. Please excuse my poor photography skills and feel free to message me with any questions.

The ASD module is attached to the sound syste amplifier and is located in the driver side rear corner of the trunk under some trim panels just in front of the driver side convertible top latch mechanism. The location (with nothing removed) is shown in this photo:



One cover, one storage tray and two trim panels need to be removed to access this area. Begin by opening the lid of the small and useless storage tray on the left side of the trunk. When you lift the lid all the way, just give it a little pull and the tabs will release from the slots, then you can remove the lid and set it aside. This photo shows the lid removed:



Then slip your fingers or a trim tool under an edge of the storage tray and pry it upward to remove it. There are no fasteners; it just comes loose with a gentle pull. This photo shows the tray removed:



Now remove all of the button fasteners around the carpeted trim piece covering the area as well as the fasteners holding the plastic convertible top latch cover in place. I didn’t count or highlight the fasteners on the carpeted trim, but they are all easy to see and easy to remove. The plastic convertible top mechanism cover is held in place by three button fasteners. All fasteners are the same, so you don’t need to remember which ones go where. Use a flat blade or trim tool to pry up the top of the fastener. Once it moves, you can pull it with your fingers and the whole unit will come out. Use gentle firm pressure but don’t force it. Once the fasteners are all removed, start by removing the plastic convertible top mechanism cover and set it aside. Now pull the carpeted trim piece out from under the trunk weather stripping (it should come out easily) and either remove it or pull it back enough to reach your hand into the amplifier area if you can get that to work (I removed mine entirely but others have said that it can be done without complete removal). If you do remove it (and when you put it back), be very careful of the convertible top mechanism and its wiring, if you push too hard or don’t free it up properly, you could damage some of those parts. Once the trim covers are removed, it will look like this:



The rest is pretty simple. The part that you’ve exposed is the sound system amplifier and the ASD unit is attached to it at the rear end (toward the taillight). It is the part circled in this photo:



The wiring harness is held in place by a locking lever, which when rotated will free the harness from the unit. In order to release the lever, press the small plastic tab in with your finger or a screwdriver and then lift the lever and the harness will come out. This photo shows the harness close-up:



Once the harness is removed, cover the open end with a piece of electrical tape and secure it to its own wire or something else with a zip tie or electrical tape. I ended up just looping mine back around itself and securing it that way. When it’s removed and secured, the area will look like this:



Now just reinstall all of the trim pieces you removed using the button fasteners. Again, if you removed the carpeted floor trim, be patient and careful putting it back so that you don’t damage any of the wiring or equipment in that area.

The whole project took me about 30 minutes, so not a big time investment. The harness is easy enough to remove and replace, so I tried it out both ways a few times (making sure I completely shut off the ignition before removing or replacing the harness) to make sure I liked the new sound before I put it all back together. In my case, with the M Performance Exhaust, it was an easy decision; the natural sound of the car without artificial “enhancement” is far superior. However, it is a personal choice and many disagree, so this is a relatively painless way to try it both ways before making a permanent decision. You could even leave the trim off for a few days and try it out connected and disconnected over a longer period of time. If you do that, I would suggest replacing at least the plastic convertible top mechanism cover because it protects the wiring and motors in there and it’s very easy to remove and reinstall.

P.S. I'm told this only applies to the HK sound system, but I have not verified that myself.

[ciaranob]

Your pics are no longer visible/uploading - can you rectify - primarily want to see the unit in place i.e. location? Thx, C.

[drgmt]

I just coded this off with bimmercode app. Then put it back on as I prefer It on.