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

Aftrmat

Member
Joined
Mar 12, 2022
Threads
2
Messages
21
Reaction score
6
Location
Fresno ca
First Name
Alexander
Vehicle(s)
2021 mustang gt
How’s it going ladies and gentlemen. Today I was washing my car when I noticed a noise coming from under the fuse box in the engine bay. Sounds like the pcm is making a beepin/humming noise when the car is off.
This is the first time I hear it. Car is completely stock 2021 mustang gt 10 speed. Anyone else have or had this issue? Don’t want to schedule a dealer visit but may have to since it’s never made this noise and if it’s the pcm going bad don’t want to get stranded else where. Car has less then 5k miles on it.

 

Vlad Soare

Well-Known Member
Joined
Jan 21, 2020
Threads
59
Messages
2,780
Reaction score
2,322
Location
Bucharest, Romania
First Name
Vlad
Vehicle(s)
2020 Mustang GT 6MT
I'm not sure we're talking about the same thing, but yes, mine makes a strange sound of an electric nature when it's off and unlocked. It's a kind of high-pitched, high frequency buzz, which lasts about two seconds and repeats every minute or so.
The strange thing is, I only hear it when I wash the car. If the car is dry and I just stand by it waiting for it to buzz, it doesn't. But it does every time I wash it.
All I can think of is that the car reacts to the water touching the door handles and thinks I'm just about to open the door, so it prepares itself for starting (perhaps priming the fuel system, or waking up some electronic components, or something like that).
 

ice445

Well-Known Member
Joined
Apr 13, 2020
Threads
24
Messages
4,489
Reaction score
4,864
Location
Salt Lake City, UT
First Name
Ryan
Vehicle(s)
2020 Mustang GT 6MT
Yeah the car has some pre start calibrations that it does, you can hear it adjusting various items (I assume IMRC and throttle body are included). Seems to be related to unlocking the car and opening the door.
 

MCS

Well-Known Member
Joined
Aug 31, 2021
Threads
38
Messages
1,122
Reaction score
1,166
Location
SW Ontario
First Name
Michael
Vehicle(s)
2021 GT Premium
I actually hear this as well when unlocking my door and climbing in. I think it's closing the active exhaust valves for a quiet start as well as changing other setting to full on sexy sexy mode. At least that's what I tell myself.
 

GetSum2112

Active Member
Joined
Sep 18, 2021
Threads
1
Messages
27
Reaction score
59
Location
Olney, MD
First Name
Steve
Vehicle(s)
2021 GT - TO, AE, BO, 10 SP & 301A
Mine does what MCS describes, but I dont think it's what the OP is referencing. I've never heard what Aftrmat is talking about. mine's bone stock 21 also.
 


velocityblue5.0

Well-Known Member
Joined
Sep 5, 2021
Threads
18
Messages
820
Reaction score
781
Location
new jersey
Vehicle(s)
2021 Mustang GT Premium, 2007 Toyota Tacoma
I'm not sure we're talking about the same thing, but yes, mine makes a strange sound of an electric nature when it's off and unlocked. It's a kind of high-pitched, high frequency buzz, which lasts about two seconds and repeats every minute or so.
The strange thing is, I only hear it when I wash the car. If the car is dry and I just stand by it waiting for it to buzz, it doesn't. But it does every time I wash it.
All I can think of is that the car reacts to the water touching the door handles and thinks I'm just about to open the door, so it prepares itself for starting (perhaps priming the fuel system, or waking up some electronic components, or something like that).
or she’s just happy to be getting a bath and showing you her appreciation!
 
OP
OP
Aftrmat

Aftrmat

Member
Joined
Mar 12, 2022
Threads
2
Messages
21
Reaction score
6
Location
Fresno ca
First Name
Alexander
Vehicle(s)
2021 mustang gt
the noise im hearing is different from when I open my doors I recorded a little video when I had the hood open. I’ll post it here give you guys a little more of a understanding of those odd noise
Thanks again for everyone replying
Really appreciate it
 
OP
OP
Aftrmat

Aftrmat

Member
Joined
Mar 12, 2022
Threads
2
Messages
21
Reaction score
6
Location
Fresno ca
First Name
Alexander
Vehicle(s)
2021 mustang gt
 

StangTime

Well-Known Member
Joined
Apr 16, 2019
Threads
57
Messages
2,788
Reaction score
2,863
Location
Ontario 🇨🇦
First Name
Todd
Vehicle(s)
19' GT PP1 Manual
OP
OP
Aftrmat

Aftrmat

Member
Joined
Mar 12, 2022
Threads
2
Messages
21
Reaction score
6
Location
Fresno ca
First Name
Alexander
Vehicle(s)
2021 mustang gt
Normal behavior. Mine does this too.
mine never did this until just yesterday
Didn’t do anything different in method washing that’s why my reaction was a bit worried Thanks for the reply might be just a normal thing.
 
OP
OP
Aftrmat

Aftrmat

Member
Joined
Mar 12, 2022
Threads
2
Messages
21
Reaction score
6
Location
Fresno ca
First Name
Alexander
Vehicle(s)
2021 mustang gt
I'm not sure we're talking about the same thing, but yes, mine makes a strange sound of an electric nature when it's off and unlocked. It's a kind of high-pitched, high frequency buzz, which lasts about two seconds and repeats every minute or so.
The strange thing is, I only hear it when I wash the car. If the car is dry and I just stand by it waiting for it to buzz, it doesn't. But it does every time I wash it.
All I can think of is that the car reacts to the water touching the door handles and thinks I'm just about to open the door, so it prepares itself for starting (perhaps priming the fuel system, or waking up some electronic components, or something like that).
I posted a video. If you can watch it to see if it’s the same noise we are hearing.
 
OP
OP
Aftrmat

Aftrmat

Member
Joined
Mar 12, 2022
Threads
2
Messages
21
Reaction score
6
Location
Fresno ca
First Name
Alexander
Vehicle(s)
2021 mustang gt
Mine does what MCS describes, but I dont think it's what the OP is referencing. I've never heard what Aftrmat is talking about. mine's bone stock 21 also.
posted a video
Something to watch out for next time you wash your car see if it’s a normal thing
 

NeverSatisfied

Well-Known Member
Joined
Apr 8, 2020
Threads
18
Messages
286
Reaction score
214
Location
Pittsburgh
First Name
Matt
Vehicle(s)
2021 GT 6MT Base
My ‘21 does it randomly too when off. Just assumed its something emissions related.
 
OP
OP
Aftrmat

Aftrmat

Member
Joined
Mar 12, 2022
Threads
2
Messages
21
Reaction score
6
Location
Fresno ca
First Name
Alexander
Vehicle(s)
2021 mustang gt
My ‘21 does it randomly too when off. Just assumed its something emissions related.
Thanks for reply
I’m guessing it’s relatively normal thing then
I’m new to the platform so I’m unfamiliar with it.
 

MCS

Well-Known Member
Joined
Aug 31, 2021
Threads
38
Messages
1,122
Reaction score
1,166
Location
SW Ontario
First Name
Michael
Vehicle(s)
2021 GT Premium
Geez, that is enough to make someone paranoid as hell. Like is there a small digital clock attached to it with red numbers... that count backwards to 0?!?!?!
 

 
15 - Steeda - 1
Top