High pitched whine?

[FML]

Do you have the heated/cooled seats?

I have noticed that there is a noise that comes from these.

 

[JoeSC]

I haven't figured out what it is, but I've had it after shutting off my '17 before. But I've never had it while driving. I saw someone else mention it yesterday too, but I think they have it the same what i do. Mine is infrequent, so it must be for something I rarely use. I've only noticed it without a passenger.

 

[FordTechOne]

I haven't figured out what it is, but I've had it after shutting off my '17 before. But I've never had it while driving. I saw someone else mention it yesterday too, but I think they have it the same what i do. Mine is infrequent, so it must be for something I rarely use. I've only noticed it without a passenger.

Does this sound like what you're hearing?

SSM 49203 - 2017-2020 F-150 - Externally Controlled Variable Displacement Compressor - HighPitched Squeal/Whistle Noise From The Engine Compartment After Engine Shut Off
Some 2017-2020 F-150 vehicles equipped with a 3.5L EcoBoost engine, 2018-2020 F-150 vehicles equipped with a 2.7L EcoBoost or 5.0L engine, 2019-2020 F-150 vehicles equipped with a 3.0L engine, may exhibit a high pitched squeal or whistle type noise from the engine compartment after the engine is shut off. This condition may be due to the air conditioning (A/C) low side system pressure exceeding the high side pressure resulting in equalization of A/C system pressures through the A/C compressor. This noise is not detrimental to system operation or durability.

 

[slingshot60]

First I’ve heard of it, but it may be an issue with your audio system. Do you have any aftermarket electronics or modifications? Even something as simple as a cell phone charger can sometimes induce electrical noise into a vehicle.

Try removing the fuse for Audio Control Module (ACM), which is Fuse 33 in the BCM (behind right side kick panel). If the noise stops, it’s audio system related.

Bingo! It started making the whine again this morning, I pulled the #33 fuse and it stopped. Put it back in, went through a couple driving cycles and it started up again--pulled the fuse again and immediately stopped. Just took it to my local dealer and showed them, tech said yes--definitely ACM related and ordered a replacement unit. Will let you know if this fixes it. Thanks so much. Love this forum already!

 

[787driver]

Sounds like a bad Ground wire.

 

[JoeSC]

Does this sound like what you're hearing?

SSM 49203 - 2017-2020 F-150 - Externally Controlled Variable Displacement Compressor - HighPitched Squeal/Whistle Noise From The Engine Compartment After Engine Shut Off
Some 2017-2020 F-150 vehicles equipped with a 3.5L EcoBoost engine, 2018-2020 F-150 vehicles equipped with a 2.7L EcoBoost or 5.0L engine, 2019-2020 F-150 vehicles equipped with a 3.0L engine, may exhibit a high pitched squeal or whistle type noise from the engine compartment after the engine is shut off. This condition may be due to the air conditioning (A/C) low side system pressure exceeding the high side pressure resulting in equalization of A/C system pressures through the A/C compressor. This noise is not detrimental to system operation or durability.

Sorry I didn't see this earlier. Yeah, that could definitely be it. It probably is considering the times I remember hearing it. It's been cool-ish here lately and I haven't run the A/C very frequently and I also haven't heard that sound for a bit.

 

[slingshot60]

Update: Well... after 3 trips to the dealership and 2 trips by their audio tech to my office they finally got the necessary info to order the new ACM (Audio Control Module) and I had it installed today. Fingers crossed but so far the whine is GONE. Hallelujah!!!

 

[slingshot60]

Just as FordTechOne predicted (Thanks Again!!!) the diagnostic test is to pull fuse #33 and if it eliminates the whine it is the ACM...