2021 mustang gt making a beep / humming noise from PCM while off

[Vlad Soare]

In the meantime the sound has become a bit louder, which made me realize that it's there all the time, not just when I wash the car. I can now clearly hear it from inside the house.
There's no one near the car, nothing touches it. The key is not in range.
The noise is very regular. It does it precisely every 29 seconds.
Whether the car is locked or not makes no difference.

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[Cobra Jet]

There was a similar thread like this a few months back... it turned out to be either a dash cam or radar detector that was causing the noise... do you have either?

 

[Vlad Soare]

Nope. Nothing of the sort.
The noise seems to be coming from under the hood. I will try to record it.

 

[Vlad Soare]

This is it. You may have to turn the volume up a bit.




Every 29 seconds.

 

[EFI]

Mine does that exact noise, it's coming from the AC unit in the engine bay and it's always after I use the AC during the previous drive. If I don't use the AC, it never happens but the moment I even turn it on even for a few seconds, it makes that noise after shutting down. It gets further and further apart and eventually stops.

 

[Vlad Soare]

Mine does that exact noise, it's coming from the AC unit in the engine bay and it's always after I use the AC during the previous drive. If I don't use the AC, it never happens but the moment I even turn it on even for a few seconds, it makes that noise after shutting down. It gets further and further apart and eventually stops.

Mine doesn't ever stop. The car was parked for two weeks while I was on vacation, and when I got back home I heard it. I drove it yesterday, didn't touch it today at all, and it's still doing it as I'm writing this. And the frequency is unchanged - precisely every 29 seconds. I wonder why not 30.

 

[Vlad Soare]

Guys, I've a confession to make. I'm stupid.
It's not the car. It's this cable TV box, which is about thirty yards away from the spot where the car is parked:




I don't know how the sound reflects off the houses/fences/etc. so that it seems as if it were coming from my car.

 

[Firsttexan]

I haven't heard it. But I am deaf in one ear. Too many years of hot cars, guns and loud music.

My audiologist tells me I can't hear the frequency that women and children talk in.

Overall a blessing.

So I am likely to miss high pitched frequencies.

 

[dx2]

Hard to hear what it wants to tell you, it's quite hard to understand their language, especially if it is directly throwing binary code over the air. we humans are not advanced enough yet to interpret their superior code.

maybe 'hug me' or 'I desperately need a tune' ?

 

[Cobra Jet]

Guys, I've a confession to make. I'm stupid.
It's not the car. It's this cable TV box, which is about thirty yards away from the spot where the car is parked:




I don't know how the sound reflects off the houses/fences/etc. so that it seems as if it were coming from my car.

Oh geez... interesting none the less ... but at least you located the source!

 

[Vlad Soare]

Yeah, it's strange how sounds can so easily seem to come from a completely different direction.
I spent quite some time yesterday sticking my head under the bonnet and trying to figure out where it was coming from. It seemed to be coming from everywhere and nowhere, but from the car nonetheless.
Sorry, guys. False alarm. The car is fine.

 

[PoCoBob]

Guys, I've a confession to make. I'm stupid.
It's not the car. It's this cable TV box, which is about thirty yards away from the spot where the car is parked:



I don't know how the sound reflects off the houses/fences/etc. so that it seems as if it were coming from my car.

This makes sense since 29 seconds is the exact amount of time any guy will watch a TV program before he hits the remote to see what's on another channel.

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