• Register Today It's free! This box and some ads will disappear once registered!

Adaptive Cruise Control/Brake Charge Hum

MattHelm21

Member
Joined
November 22, 2015
Messages
12
Reaction score
0
Year, Model & Trim Level
2016 Explorer Platinum
Hi,

I searched for this and have been unable to find anything similar so apologize if this has been already answered elsewhere. I love everything about the Platinum including the ACC. I picked this up at the end of November and can't recall if this has occurred since new but I don't remember it which may be because I either did use the feature much or always had the radio on.

When using ACC, and when either the system detects a slow vehicle in front of me or if it otherwise detects over speed, there is a humming for about 2 to 3 seconds before the brakes are applied. I assume this is some kind of pump precharging the brake system but should it be loud enough to hear over road noise and sometimes the radio? Does anyone else experience this in normal operation? I'm planning on taking it into the dealer.

Thank you,
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private Conversations, and more. Join Today. Your support is greatly appreciated.




peterk9

Staff member
Moderator
Elite Explorer
Joined
December 28, 2010
Messages
30,031
Reaction score
2,066
City, State
Russell, Ontario (Ottawa area)
Year, Model & Trim Level
2020 Aviator Reserve
Callsign
VE3
Hi,

I searched for this and have been unable to find anything similar so apologize if this has been already answered elsewhere. I love everything about the Platinum including the ACC. I picked this up at the end of November and can't recall if this has occurred since new but I don't remember it which may be because I either did use the feature much or always had the radio on.

When using ACC, and when either the system detects a slow vehicle in front of me or if it otherwise detects over speed, there is a humming for about 2 to 3 seconds before the brakes are applied. I assume this is some kind of pump precharging the brake system but should it be loud enough to hear over road noise and sometimes the radio? Does anyone else experience this in normal operation? I'm planning on taking it into the dealer.

Thank you,
I had the system in my 2011 Limited and never heard any such sound.

Peter
 




cwescapexlt4x4

Explorin' the Desert SW
Elite Explorer
Joined
May 3, 2005
Messages
1,378
Reaction score
47
City, State
Litchfield Park, AZ area...
Year, Model & Trim Level
2016 Explorer LTD (FWD)
i haven't heard it in mine either but typically between road noise (not bad) and or windows down/stereo up i wouldn't hear it.
 




wifes2011xlt

Well-Known Member
Joined
February 11, 2014
Messages
390
Reaction score
3
City, State
IL/WI border
Year, Model & Trim Level
2015 Limited (wife's)
We've taken our Explorer on 2k+ mile round trip road trips twice with ACC engaged as much as possible and have never heard this hum of which you speak.
 




Napalm

Well-Known Member
Joined
June 18, 2015
Messages
760
Reaction score
30
City, State
Memphis tn
Year, Model & Trim Level
2016
Hi,

I searched for this and have been unable to find anything similar so apologize if this has been already answered elsewhere. I love everything about the Platinum including the ACC. I picked this up at the end of November and can't recall if this has occurred since new but I don't remember it which may be because I either did use the feature much or always had the radio on.

When using ACC, and when either the system detects a slow vehicle in front of me or if it otherwise detects over speed, there is a humming for about 2 to 3 seconds before the brakes are applied. I assume this is some kind of pump precharging the brake system but should it be loud enough to hear over road noise and sometimes the radio? Does anyone else experience this in normal operation? I'm planning on taking it into the dealer.

Thank you,

The platinum model probably has a bit more sound deadening in the cabin than the others.

do you only hear with if the radio is off?

If that is so I would suspect you could be hearing the ABS actuator pump motor coming on. I would however think it is always charged though as it would have to be read activated for whenever you apply your brakes - not just with the ACC system on.


You might - however - be hearing the gentle application of your brakes. IE a very light application of the brakes would press the pads all on the rotors - and that light application would make a slight noise. Could sound like whirring, or rubbing. Not sure - light brake application would be difficult to replicate when your foot.

That's the first 2 thoughts that come to mind. I don't have ACC on my explorer so I've got no direct comparison.
 




chicagoslick

Well-Known Member
Joined
December 17, 2013
Messages
106
Reaction score
0
City, State
Indianapolis Indiana
Year, Model & Trim Level
2016 Explorer Platinum
I have had 4 different vehicles with ACC and do not recall ever hearing the noise your are describing. I will listen closer tonight and respond back tomorrow.

My first thoughts would be the collision avoidance system pre-loading the brakes causing the sound. It should not be that noticeable, though...
 




MattHelm21

Member
Joined
November 22, 2015
Messages
12
Reaction score
0
Year, Model & Trim Level
2016 Explorer Platinum
I don't think I could hear it until maybe a month ago. The hum always precedes the application of the brakes and then stops as the brakes are applied. If it is a long gentle downgrade requiring repeated application of the brakes to maintain speed, this may cycle several times. 2 second hum then brake, 2 second hum then brake.

I listened for it on the way home tonight and have to strain to hear it with the radio on but I do hear it. With the radio off, it is noticeable and annoying. I have to schedule my first oil change and I'm going to have it looked at.

Thanks for all the replies.
 




chicagoslick

Well-Known Member
Joined
December 17, 2013
Messages
106
Reaction score
0
City, State
Indianapolis Indiana
Year, Model & Trim Level
2016 Explorer Platinum
I listened for it last night on the way home from work and did not notice any humming noise whatsoever. With that said, I did spend some time thinking about the noise you described and I recall an instance with my Buick GN ( I know old and not similar in type or system) where the Power Master brake unit started to fail and made this type of noise.

On the Buick GN's they used an electric brake booster pump and and accumulation bowl. When issues started to arise with the system it was not long before the system failed completely.

As you stated you were going to have it looked at. I would really push them if you suspect brakes. If the system fails it will most likely cripple the brakes. Not a good situation while driving.

Best of luck and keep us informed...
 




peterk9

Staff member
Moderator
Elite Explorer
Joined
December 28, 2010
Messages
30,031
Reaction score
2,066
City, State
Russell, Ontario (Ottawa area)
Year, Model & Trim Level
2020 Aviator Reserve
Callsign
VE3
I listened for it last night on the way home from work and did not notice any humming noise whatsoever. With that said, I did spend some time thinking about the noise you described and I recall an instance with my Buick GN ( I know old and not similar in type or system) where the Power Master brake unit started to fail and made this type of noise.

On the Buick GN's they used an electric brake booster pump and and accumulation bowl. When issues started to arise with the system it was not long before the system failed completely.

As you stated you were going to have it looked at. I would really push them if you suspect brakes. If the system fails it will most likely cripple the brakes. Not a good situation while driving.

Best of luck and keep us informed...
From reading the posts it seems this is caused by the system precharging the brakes and only occurs when conditions for the automatic self braking are detected. It doesn't seem to affect manual braking. I'm not familiar enough about the systems to know for sure if manual braking would be affected if the other system malfunctions.

Peter
 




chicagoslick

Well-Known Member
Joined
December 17, 2013
Messages
106
Reaction score
0
City, State
Indianapolis Indiana
Year, Model & Trim Level
2016 Explorer Platinum
From reading the posts it seems this is caused by the system precharging the brakes and only occurs when conditions for the automatic self braking are detected. It doesn't seem to affect manual braking. I'm not familiar enough about the systems to know for sure if manual braking would be affected if the other system malfunctions.

Peter

Like you Peter, I'm not familiar enough with the system. However, I would be willing to bet that most of the components are shared. I would be cautious about the braking system in general.
 




MattHelm21

Member
Joined
November 22, 2015
Messages
12
Reaction score
0
Year, Model & Trim Level
2016 Explorer Platinum
Thanks everyone. I will post back as soon as I get the service done.
 




3.5TT

New Member
Joined
October 28, 2015
Messages
4
Reaction score
0
City, State
Black Diamond, WA
Year, Model & Trim Level
2020 Explorer ST
My 2016 Explorer Sport with ACC makes the same sound going down a gentle hill. I assume it's the sound of the ACC working. I have only had one other vehicle that braked itself going down hill using cruise control just like my Explorer. Please do let us know.
 




MattHelm21

Member
Joined
November 22, 2015
Messages
12
Reaction score
0
Year, Model & Trim Level
2016 Explorer Platinum
Well today it is in for service. I was not thrilled when the service writer said he thought the hum would turn out to be normal before anyone looked at it.

I called at 3:00 p.m. to get a status and was told they were unable to detect the hum I mentioned. However, they asked if they could keep it the rest of the day to find some hills to do a little more testing. That at least is encouraging.

My plan, if I'm told this is normal is to request a test drive in another Platinum and if I don't detect the noise then request a technician or the service manager go for a ride with me.
 




MattHelm21

Member
Joined
November 22, 2015
Messages
12
Reaction score
0
Year, Model & Trim Level
2016 Explorer Platinum
I got it back from service today. No trouble found. The service writer went for a ride with me and I pointed the noise out to him but of course it had to snow today so the roads were all wet raising the road noise so even I had to strain to hear it. The writer said he couldn't hear anything abnormal but he was going to check with Ford and let me know what they say. I expect to hear back from him next week some time.
 




Joined
December 12, 2018
Messages
19
Reaction score
0
City, State
Connecticut
Year, Model & Trim Level
2017 Sport
Any response back on this one? I have a 2017 with the same exact noise.
 




peterk9

Staff member
Moderator
Elite Explorer
Joined
December 28, 2010
Messages
30,031
Reaction score
2,066
City, State
Russell, Ontario (Ottawa area)
Year, Model & Trim Level
2020 Aviator Reserve
Callsign
VE3
Any response back on this one? I have a 2017 with the same exact noise.
FYI, the originator of the thread has not been active here since July 22, 2016.

Peter
 




Joined
December 12, 2018
Messages
19
Reaction score
0
City, State
Connecticut
Year, Model & Trim Level
2017 Sport
Thanks for the heads up, I'm taking mine in tomorrow but don't have high hopes... problem is I'm going to be using ACC all the time...so want to get it figured out but there isn't much out there about it, even after searching it up a bunch..
 




jhu8

Well-Known Member
Joined
March 23, 2018
Messages
403
Reaction score
48
City, State
Maryland
Year, Model & Trim Level
17 Ford Explorer Limited
I get the same exact noise on my 17 limited with this feature. It is very noticeable and happens right before the vehcive begins to slow. I always assumed it was normal and still do. Just a matter of what it actually is. It would be nice to know.
 




Joined
December 12, 2018
Messages
19
Reaction score
0
City, State
Connecticut
Year, Model & Trim Level
2017 Sport
I get the same exact noise on my 17 limited with this feature. It is very noticeable and happens right before the vehcive begins to slow. I always assumed it was normal and still do. Just a matter of what it actually is. It would be nice to know.
I have had this on two previous Lexus models and have used it on various other cars (mostly long term loaners) - none of them have made this noise...
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private Conversations, and more. Join Today. Your support is greatly appreciated.




jhu8

Well-Known Member
Joined
March 23, 2018
Messages
403
Reaction score
48
City, State
Maryland
Year, Model & Trim Level
17 Ford Explorer Limited
I have had this on two previous Lexus models and have used it on various other cars (mostly long term loaners) - none of them have made this noise...

Found this in a Lexus forum, titled
Adaptive Cruise Control Whine Sound.

When you're manually operating the brake pedal, it's silent as the pressure built-up inside the system that sends brake fluid to each of the wheels is generated by you, the driver. When the vehicle is controlling braking on it's own, such as when you're using adaptive cruise control, that pressure needs to build somehow, which is the humming noise you're hearing.
 




Top