Audio Issues after Forscan - ASBuilt doesn't fix

[GT FM]

Ford Mustang 2017 - Shaker 9 speaker, stock everything

To start off, I don't know what the hell I'm doing. Found out about Forscan some time ago and the ability to change car settings, did things like disable door chimes, DRL settings, auto door lock etc and everything worked well.

Came across a lot of posts regarding better audio quality if you change the ACM module code "727-01-02" to x0xx xx. Mine came standard with 727-01-02-0200 33. Saved AS-BUILT stock data, made a Forscan back up. Didn't change the checksum as I heard Forscan will do that itself. First drive and audio started popping and crackling, occasionally cutting off on the left side speakers. Shit, went back home and changed it back to as built data thinking it'd fix the issue and it didn't. Audio still doing the same thing. At first I thought it was my cable/phone but it was doing it on radio and bluetooth as well so I think I fucked up somewhere.




Things I have tried to do since then -

• Revert changes I made 727-01-02-0000 back to As Built (727-01-02-0200) and 727-01-02-0100

• Master reset on the Sync 3 software via Settings

• Different combinations of the above

• Disconnecting the negative terminal on the battery for 5 hours to reset electrical system

• Taking apart the footwell and finding the amp location, sprayed WD-40 contact cleaner on Black + Gray + Brown plugs and terminals (Done with battery disconnected)

• Check fuses and switch them around with another fuse

• Grabbed a hair dryer and put heat near the Amplifier and Speakers causing issue - Doesn't replicate issue that actual heat from outside causes

Symptoms -

• Audio pops and crackles on left side tweeter and top door speaker, occasionally cuts off for a few seconds

• Audio only pops and crackles when something is playing through the speakers. If it's off, there's no issue

• Crackles and pops can happen at any volume, however how loud it pops and crackles is dependent on the volume level

• Audio sounds completely normal when it's working, all speakers working and producing sound perfectly at all volumes

• Happens when it's hot outside/inside the car. Does not happen in cold weather or when parked up

• Has progressively gotten better, was previously doing it all the time, now it only cuts/pops/crackles for a second or two every 10 minutes or so

• Nothing I have done has fixed it

I've also played around max volume/max bass/no bass/treble/mids, moved around the fade and balance to every single possible setting (focus on front left speaker/right rear etc). It makes no difference in either getting it to replicate my problem or fixing it. It just does it whenever it wants, whether it's 20 minutes into troubleshooting or nothing at all or 10 mins into it.

I've maxed out the sound + bass in hopes that maybe it'll shake the shit out of the door enough that it could tell me that it's the wiring touching something it's not supposed to or doing something funky. Can't replicate the issue either.

Also hair dryer to heat up the amp and speakers, both together and seperately to try and replicate the issue and force them to pop/crackle so I 100% know it's heat related. Makes no difference either.

It's really messing with me trying to figure this one out.

I have taken it to an audio guy and I mentioned the possibility of it being the wiring or a bad ground. Went for a test drive and he said 50-50 wiring or bad amp. Told me if I wanted an amp they had a 12 channel one for $3000. Called Ford parts and they were shocked someone would ask for an amp, guy said he never sold one before and that it was $1150 for a new one. Can get used factory amps online if it makes a difference. I don't really have the skills/know how/tools necessary to mess around with electrical parts or test voltages etc. Not sure what to do next.

[Lightning_blue]

Hi, any updates on the issues you had? I have a '17 with the 9 speaker and was thinking of trying the same thing, but was hesitant after reading your post. I know it was pretty recent, but I wonder if you've made any headway? Sorry I can't be of actual help, just didn't want to end up in the same boat.

[Don Ridley]

Did you revert the door chime changes?

[GT FM]

Hi, any updates on the issues you had? I have a '17 with the 9 speaker and was thinking of trying the same thing, but was hesitant after reading your post. I know it was pretty recent, but I wonder if you've made any headway? Sorry I can't be of actual help, just didn't want to end up in the same boat.

No update as nobody really knows what's going on, as far as I know, nobody has had issues with this other than myself. I posted it on a few other websites and so far no answers too. I'm waiting for a used amp to come through the mail and will replace the old one and see if it fixes it. If it does I will post an update.

Did you revert the door chime changes?

I didn't make changes to the door chimes but I have reverted my 727-01-02-****-** back to As Built (727-01-02-0200) and it made no differences

[Fabuxo]

Try to flash ACM firmware again with latest version of Forscan 2.4.
Worth a try.

if this didn´t solve, try to do a module reset after...

[Don Ridley]

The ACM is a pretty simple module compared to the BCM, PCM, APIM etc. I don't know anything about the stock amps except there is a "smart amp" setting that may be impacting you.

My suggestions:

1. First, visually compare the current ACM configuration with the original configuration.
2. You can create a text copy of the .ab file using Windows notepad (you have to separate the address and data manually) or as built explorer. http://www.compulsivecode.com/Project_A ... mpare.aspx
3. Load a complete copy of the as built data using the Load Factory Data button on the as built data page. This will ensure all data fields are written with the proper data.

If you made any other changes with Forscan, especially in the APIM, you may need to reset them. You may have to research how the amp works with your ACM. I appears that the smart amp gets a high, constant voltage from the ACM and the APIM controls the volume by adjusting the amp gain (output). This may be the source of the problem.

[GT FM]

Try to flash ACM firmware again with latest version of Forscan 2.4.
Worth a try.

if this didn´t solve, try to do a module reset after...

I tried doing a module rest on both the APIM and ACM and it didn't help. I would flash a new ACM firmware but I'm not confident enough with that, might end up bricking it for no reason.

The ACM is a pretty simple module compared to the BCM, PCM, APIM etc. I don't know anything about the stock amps except there is a "smart amp" setting that may be impacting you.

My suggestions:

1. First, visually compare the current ACM configuration with the original configuration.
2. You can create a text copy of the .ab file using Windows notepad (you have to separate the address and data manually) or as built explorer. http://www.compulsivecode.com/Project_A ... mpare.aspx
3. Load a complete copy of the as built data using the Load Factory Data button on the as built data page. This will ensure all data fields are written with the proper data.

If you made any other changes with Forscan, especially in the APIM, you may need to reset them. You may have to research how the amp works with your ACM. I appears that the smart amp gets a high, constant voltage from the ACM and the APIM controls the volume by adjusting the amp gain (output). This may be the source of the problem.

I did that earlier during troubleshooting. Also double checked on the Ford motorcraft website for my exact VIN on both the ACM and APIM. Everything matches up with the current files in the car and the back up .abt files that I had made originally before making the changes to the car. The car is now on stock ACM and APIM files.

I should also mention Forscan testing and DTC reveals no issue with the APIM/ACM/DSP.

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I've thought about it possibly being a physical issue rather than just straight software issue being that either the changes could have burnt up something inside the amplifier due to the changes made or it could have been something unrelated that popped up right after the forscan changes.

I also finally received the used amplifier which was a U.S model compared to the international model Mustang that I have. The numbers on the stamping all match up, physically it's all the same (YanFeng Visteon S69GA) and it's from a 2017 model Mustang. It also didn't solve my issue.

I'm guessing while the amplifier was the same, there's some differences internally/coding wise as when I plugged the U.S amplifier in, I had static background noise from Vol 1, it also didn't solve my issue of the crackling/popping/cut off on the left tweeter and left top speaker (same channel to amp). Since it was worse, I plugged in my original amp and left it as is for now as I'm basically out of skill at this point.

I took it to a specialist audio installation shop a few weeks ago who had a listen and said it was 50/50 amp or wiring. They're almost certain it's the wiring at this point so I have an appointment with them in 3 weeks time. I'll update this thread in the future if there's any updates or if they managed to fix it.

[Don Ridley]

You have done all the "software" type checks I can think of. Since your replacement amp appears to have the same problem, you could have a faulty ACM. ACMs in the US are easy to find for around $150. I would try connecting speakers directly to the ACM and change the ACM settings for "internal amp". If those speakers pop then the ACM is bad. But this will not rule out a problem with the ACM-AMP connection and function.

The audio shop should be able to figure this out. I don't know if they can make ACM configuration changes that may help the troubleshooting process.

[GT FM]

You have done all the "software" type checks I can think of. Since your replacement amp appears to have the same problem, you could have a faulty ACM. ACMs in the US are easy to find for around $150. I would try connecting speakers directly to the ACM and change the ACM settings for "internal amp". If those speakers pop then the ACM is bad. But this will not rule out a problem with the ACM-AMP connection and function.

The audio shop should be able to figure this out. I don't know if they can make ACM configuration changes that may help the troubleshooting process.

Yep, have thought about it being the ACM too. As far as I know, European models and U.S models have different ACM configurations so it's not a simple swap. I've seen multiple threads on the mustang forums of people importing mustang's with base units trying to upgrade to Sync 3 with odd issues requiring heavy Forscan troubleshooting.

I could get a known working mustang ACM locally for about $500, however that's probably the most expensive option at the moment so I'll leave that until it's confirmed that it is the ACM module that's gone bad. So far the amp was $110~ USD delivered.

It could also just be a bad ground or wiring, at this point I don't really know. I'll leave it to the shop and see where to go from there.

[joelane]

I THOUHGT THAT NUMBER WAS 727-01-02 0100-..AT LEAST IS IS ON MY 2017 F150..THEN CHANGED TO 727-01-02 0000..I HOPE YPU HAVE IT FIGURED OUT BUD.