ACM As-Built help - '18 Fusion ACM in a '14 Fusion

Hello, I am wondering if anyone out there could provide a bit of guidance on some As-Built changes for an ACM from a 2018 Ford Fusion that I have put in to a 2014 Ford Fusion.

I originally had DS7T-19C107-BK in my Fusion and I swapped it with HS7T-19C107-ZD.

Everything seems to working fine options wise, but my issue stems with the ACM sending out high voltage through the speaker wires.
On the '14 original ACM, I changed to a flat variable output voltage and I was consistent voltage across test tones with max volume and unclipped.

I made (what I think are the correct changes) in the '18 ACM As-Built to do the same thing, but of the changes I’ve made so far, I now clip at various volume levels on different test tones (strongest tone I tested was 400Hz where it clipped at 22/30 volume) and my voltage output before clipping now is around 8V. I tried a couple changes in the As-Built, but no results yet for what I am seeking. Another thing I noticed too now is my rear speakers are rolling off the bass big time in higher volumes (fronts are not) and I believe I changed to a flat response as well, but obviously something is not right! I know there are some differences between the two ACM’s, but from what I was locating, it seemed that everything regarding speaker output was in the same build code lines.

I am sure there are others out there way smarter than I, that may be able help point me in the right direction!

Original As-Built data on the '18 ACM (in brackets is what I have changed it to for now) is:

727-01-01 - 1809 1808 0576 (185A 3800 01DB)
727-01-02 - 0100 0001 0033 (0033 0001 0065)
727-01-03 - 0000 0000 0032 (Same)
727-02-01 - 1344 (Same)
727-03-01 - 386A (Same)
727-04-01 - 0002 0143 41BA (Same)

I can certainly provide more details if needed.

Thank you!

Someone might be able to offer better advise that me but as a starting point have you check the asbuilt values with our databases?

Yes, sorry. That was my starting point when I was comparing values between the two. I also relied on some info I found that was detailed in a spreadsheet for F-150’s that broke down the same things.

I may need to create my own comparison sheet between the two specific ACM’s as I know there are some differences between the two. It just didn’t appear (to me anyway) that the differences were going to have an affect on output voltage of the speaker wires.

I wouldn’t think they would, to be fair UK ACM’s don’t have much configuration well on the cars i’ve had atleast so i’m not much help on ACM AsBuilt, maybe someone else will know more, especially in regards to the F-150, @F150Chief :wink:

Thanks! I am hoping I have just overlooked something simple.

HS7T-19C107-ZD is a 2017 design unit used in 2018 vehicles. It is not equipped with A2B, however this one has the A2B firmware by looking at the asbuilt.

Right now, I can see that you have voltage issues and bass roll off, probably related to channel mixing. Keep in mind that the rear channels originate the bass (sub) in these systems without a sub, so you will see roll off there. If you plan on driving a subwoofer, sample from the front channels or use the sub output of the ACM. There is some protection filtering on the sub outputs of the ACM, be aware of that. It may or may not be a concern, depending on your musical tastes. It might be just as well to use the front channels only to drive aftermarket equipment and split the channels there.

Unless you are using a standard resistor load of 4 or 8 ohms, your measurements will not be accurate due to the speaker response of the built-in crossovers in the speakers. Also, if you are using a voltmeter for this test, you will need to terminate the speaker outputs with the appropriate resistance, as the voltmeter input impedance is probably 10K Ohms.

This is what I suggest, first some explanation…see the attached spreadsheet.
727-01-01 xx59 F8x8 xxxx = Enables Line Level with Optional Subwoofer (Aux 1) and Front Center (Aux 2) Outputs Enabled.
727-01-02 00xx xxx0 xxxx = Disables Factory EQ Processing and Disables A2B Slave Configuration.

727-01-01 breaks down as follows:
5 = Variable Line Level Audio Output
9 = Enable External Subwoofer (AUX 1) and Internal Amplifier (Aux 2)
A = Enable External Subwoofer (AUX 1) and External Subwoofer (Aux 2)
F = Disable Open Speaker Circuit Detection (w/Active FM Radio Antenna - Otherwise use a D for Mast)
8 = Front Tweeters Present
8 = Aux 1 Type: Mono Subwoofer and Aux 2 Type: Front Center

Try this as your NEW AsBuilt: (xx=checksum bits, let FORScan figure these.)
727-01-01 - 1859 F808 00xx = Line Level, Active Antenna, Aux 1 Type: Mono Subwoofer and Aux 2 Type: Front Center
727-01-01 - 1859 D808 00xx = Line Level, Mast Antenna, Aux 1 Type: Mono Subwoofer and Aux 2 Type: Front Center
727-01-01 - 185A F800 00xx = Line Level, Active Antenna, Aux 1 Type: Mono Subwoofer and Aux 2 Type: Mono Subwoofer
727-01-01 - 185A D800 00xx = Line Level, Mast Antenna, Aux 1 Type: Mono Subwoofer and Aux 2 Type: Mono Subwoofer

727-01-02 - 0000 0000 0031 = Disables Factory EQ Processing, Turns OFF ANC Mixing, Disables Audio A2B (Slave 1) Configuration

727-01-03 - 0000 0000 0032
727-02-01 - 1344
727-03-01 - 386A
727-04-01 - 0002 0143 41BA

KHoop ACM As Built Database.xlsx (65.1 KB)


Thanks for the detailed response! I don’t have time tonight to go over it all, but I am hoping tomorrow at some point I can dig into a bit and respond back with some findings.

What exactly is “Aux 1” and “Aux 2”?

In audio terms, these are what is referred to as “audio return channels”, sometimes referred to as AUX channels in software applications. Think of these as audio side chain (or parallel) channels within the audio processor where misc audio manipulation can be performed without disturbing the main audio channel, and re-inserted into the main audio channel downstream if desired. (Hence “return”).

An example of this in the ACM is the ANC processing. (Automatic Noise Cancelling).

What then is the difference between setting as Mono Sub or Front Center?

Maybe the physical set up of my car audio is important to note.
The set up goes as follows:

  1. ACM speaker out wires (so harness C240a pins 9,10,11,12, 21, 22, 23, 24) were cut and now feed into the inputs of a DSP I added.
  2. I input 4 channels into the DSP and output 6 channels (I am utilizing the Front Left and Front Right channels to supply a signal to a subwoofer).
  3. The DSP output channels 1 to 4 (Front and Rear speakers) feed into a 4 channel amplifier. Channels 5 and 6 feed into a 2 channel amplifier.
  4. the 4 channel amplifier feeds out speaker wire back behind the dash and connects in to other end of the speaker wires I cut in step 1 to go to the speakers in the doors.
  5. The 2 channel amplifier (bridged) feeds speaker wires in to a subwoofer in the trunk.

This is why I am trying to understand Aux 1 and Aux 2 and how it is implemented…maybe I am missing a step in the physical wiring part of my configuration? My thinking was that if Aux 1 is enabled to do something, it would make the change within the ACM, and then output the signal change through a new wire out of the harness, and I should tap that wire for signal.

That would be where the noise cancelation signals are mixed to. In different car models they will use different channels to be the most effective.

Unless the ACM specifically relates to these outputs as Aux 1 or 2, there is no relation to the settings for the Aux 1 and 2 in the asbuilt. The wires above match for the older radio (DS7T-19C107-xx) as:





This wiring also matches 2018 and some 2019 units, non-Sony/B&O.

So, I would not think wiring is an issue, after reading your first post, it’s just that there are high levels, not an issue with audio not working. I would suggest looking at the DSP input and output, and how that is wired, using high- or low-level inputs on the DSP or the likes.

I don’t know if you have seen this thread, but DanMc85 has done this long ago and has a very good write-up on it…

Variable Line Level Preamp Outputs From ACM (Factory Radio) For Amplifier Upgrades (

Thanks for the continued help and explanations on this!

So I was able to spend a small amount of time on it this afternoon.

I started off by putting the as-built back to stock and connected the factory wiring back to out of ACM right to speakers. Everything worked fine. I didn’t measure output though.

I swapped back to send ACM signal to DSP to amps to speakers and changed as-built to

727-01-01 - 185A D800 00xx
727-01-02 - 0000 0000 0031

Unloaded (no speakers connected) wires out of the ACM are again around 8V before observing clipping on my oscilloscope. I think volume was 20 or 21/30.

So I tested the output of the DSP this way and my oscilloscope showed very distorted waves like I’ve never seen before.

Now my DSP also came with RCA ends that attenuate the signal, so I put those on and it drops my ACM out voltage to around 3V if I remember correctly. Coming out of the DSP the signal waves were much better now and normal. So I set the rest up for now and will try something else another day, when I get some time to play around with it.

Feel a little defeated, but there’s more for me to play with.

I have reviewed the post on 2GFusions as I used that to modify my original ACM which worked. It’s a fantastic forum (as is this one I’m finding too!)

You could us a 600 ohm resistor across the + and - connected to the scope and the levels would be more accurate.

It seems like you have this in the bag, just a bit more tweaking on the signal levels. Glad to help, I’ve been there many times!

I’ll leave the thread open for now in case you need anything.

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