2017 Ford Edge Buzz when Headlights On

tuffsubjecttuffsubject Member Posts: 20
edited July 2017 in Ford
When we turn on our headlights, we get a high pitch buzz from the subwoofer in the back of our 2017 Ford Edge. Any idea what's going on? Had it in the shop last week for 4 days, they did some type of master reset but that didn't resolve the issue. They are thinking it may be related to the ANC feature. Not sure if links are allowed but here is a video on Facebook (blank video but you can hear the sound). https://www.facebook.com/joedenison/posts/10213690240639924

Best Answers


  • thecardoc3thecardoc3 Member Posts: 5,730
    edited June 2017
    Got to love some of the suggestions.. "Probably a bad ground connection... somewhere"

    ANC. An active noise cancellation issue is plausible. A ground connection "somewhere" as well intended as it might be is misleading and doesn't help. It isn't a "ground loop" which is a general term used by some when dealing with audio amplification when powered by household AC and that isn't going to apply here.

    Testing would best be done by first measuring the frequency of the sound. Then comparing that to potential source frequencies. For example the alternator regulator pulses the field control at 400hz. If the noise in the signal matched 400hz or a multiple of that such as 1200hz for a three phase or 1600hz for a four phase then the charging system would become suspect. One has to consider EMI https://en.wikipedia.org/wiki/Electromagnetic_interference from under hood sources. These can usually also be distinguished by frequency and multiples of the engine rpm.

    Another way that this can initially be done audibly is with a tone generator. http://www.szynalski.com/tone-generator/
    Try playing your recorded sound and varying the pitch from the tone generator at the same time to see when they are "in tune". What you will notice is there will be multiple frequencies that will blend in. A notable one in tune is 208hz. 400hz is definitely not in tune. Which leads me to ask this question. Does the noise change if the engine is running at different speeds?

    Using tools like a digital oscilloscope and since this is an audio noise setting it to display AC would be the first choice. The noise might be proven to be in the system source voltage or the amplifier power signal, that would be something within the reach of top technicians. If the sound is digital and being delivered to the amp, that is going to be beyond the scope of any kind of online discussion for now. It's safe to say that if it is digital in nature the techs will be limited to parts substitution and software updates as provided by the manufacturer. The best the techs can do is prove source voltages.
  • tuffsubjecttuffsubject Member Posts: 20
    The buzz pitch does not vary based on engine RPM. I'm sure I've gotten it to occur with the engine not running, possibly in acessory mode (the subwoofer amp must be powered on for the buzz), but I can't make it happen now.  

    It is intermittent, although it will often stay on for an entire drive round town.  Recent visit back at the Ford dealer shop was a bust...issue did not occurafter 36 hours.  It resumed this afternoon on a drive and we stopped by the shop again, it quit a few moments after they heard it.  It started and stopped a few times while I was there, but it was apparent that unless it consistently buzzes during diagnosis, they won't be able to find the source.  

    Next step a Ford engineer is going to take the car and drive it a few days to experience the problem.  After the July 4th holiday.  
  • thecardoc3thecardoc3 Member Posts: 5,730
    Well at least they will pay the engineer to spend time with this. Techs with the training and ability to solve these kinds of problems don't get paid for the time they have to invest working through it. They would get paid to change a part but if they spend a couple days figuring out what part needs to be replaced that is unpaid time for them.
  • tuffsubjecttuffsubject Member Posts: 20
    6 times in the dealer shop, latest attempt to fix it was replacing the amp and the subwoofer.   Problem persists.  Next step:  replace the audio control module.  They do not have the skill or equipment to trace where the signal is coming from.  Seems obvious they are just guessing, replacing parts.  Surprisingly, this is following Ford's technical support hotline advice.  Also seems obvious that the interference/signal is coming from an external source, is simply being amplified...until they identify the source the problem will remain.  We are giving them an ultimatum on next repair visit:  return it fixed or provide a replacement vehicle that doesn't have the issue.  We'll see how that goes.  
  • tuffsubjecttuffsubject Member Posts: 20
    Just got a call from the service manager at our dealer:  they have found a connector that had a bent pin (I'm guessing a ground pin), in a wire somehow related to the Audio Control Module.  This connector was under the carpet, had to remove the console to get to it. Technician was reportedly able to fix (and then disconnect to reproduce) the problem.   That's the best answer I could have hoped for! (vs not being able to verify...which had been the result of all previous repair attempts).  We'll see how it goes.  If I don't post again it's fixed!
  • PF_FlyerPF_Flyer Member Posts: 9,372
    Do you own a 2017 or 2018 Ford Edge? If so, a journalist would like to speak to you about your experience with the vehicle, particularly if you have children. If you're interested, please reach out to [email protected] no later than Monday, May 7, 2018. Thank you!
Sign In or Register to comment.