Adaptive cruise popping noise?

Addos

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Has anyone else heard a weird popping noise in the floor when adaptive cruise is braking and comes to a complete stop?
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Has anyone else heard a weird popping noise in the floor when adaptive cruise is braking and comes to a complete stop?
You let Adaptive Cruise brake and bring the car to a complete stop? I know it is capable of doing that but I didn't think that was the intended use. If I see stopped traffic up ahead then I always engage the brakes myself.

The sound you are hearing might be the ABS locking up when the wheels bounce over small bumps while under hard braking.
 

generaltso

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You let Adaptive Cruise brake and bring the car to a complete stop? I know it is capable of doing that but I didn't think that was the intended use.
Itā€˜s advertised as Adaptive Cruise Control with Stop and Go, so Iā€™m pretty sure thatā€™s one of its intended uses.
 

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Itā€˜s advertised as Adaptive Cruise Control with Stop and Go, so Iā€™m pretty sure thatā€™s one of its intended uses.
Wow. I would never use it for that purpose. The way traffic comes to a stop on the freeways around here......I just don't think the car will be able to stop in time. This morning I was doing 70 mph in the HOV lane with ACC on and up ahead the traffic was at a dead stop. I started braking myself. If I would have waited until the car ahead was identified by the sensors then that would have been a pretty bad day I think.....
 

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Wow. I would never use it for that purpose. The way traffic comes to a stop on the freeways around here......I just don't think the car will be able to stop in time. This morning I was doing 70 mph in the HOV lane with ACC on and up ahead the traffic was at a dead stop. I started braking myself. If I would have waited until the car ahead was identified by the sensors then that would have been a pretty bad day I think.....
I wouldnā€˜t trust it to go from 70mph to zero either. But using it in stop and go traffic should work fine.
 


breeves002

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It does just fine from 70 to zero, it will just brake ever so slightly later and harder than I would. It is smoother to not use it but it works fine. I use it all the time in traffic and it works pretty well. It even steers for you at very low speeds (and yells at you less for not having your hands on the wheel!). Its an assistance system to reduce fatigue, and you still need to pay attention to the world around you.

To answer the question, the popping noise is adaptive cruise activating (or preparing to activate) the real brakes. You only hear it at low speeds due to reduced cabin noise. I have noticed this in other vehicles as well with adaptive cruise, including non-Ford vehicles.

I'm not 100% sure what causes the noise but I suspect you're just hearing the piston in the master cylinder move as it gets ready to use the hydraulic brakes. It's "priming" the brake pedal...though you'll never feel the pedal stiff. The Mach E has an 'all-in-one' Electronic Brake Booster (EBB). It is on the other side of the shaft crossing the firewall and the brake pedal shaft goes directly into it. This is an all in one unit. Hydraulic master cylinder, ABS pump, and brake booster. The brake pedal normally does not create hydraulic pressure to actuate the brakes. The ABS module looks at various data to decide how much hydraulic brake assist is needed then applies the brakes as necessary.

I can't find information on it but in the case of a power failure there is supposed to be a mechanism to directly connect the brake pedal to the master cylinder so you can still stop in an emergency.
 
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Hey man, this post was really helpful. If you have heard it on other vehicles, then I guess it makes me worry less? It isn't the kind of sound I was expecting to hear, and thought something might be wrong. But you are right, it does activate as the car seems to be braking harder. So in gentle deceleration I don't hear it, only when it is trying to come to a complete stop. It just startled me, and I didn't know if the sound was normal or not. There didn't seem to be anything in the manual warning users of the feature that the sound would be heard and that it would be considered normal if it was being heard.

It does just fine from 70 to zero, it will just brake ever so slightly later and harder than I would. It is smoother to not use it but it works fine. I use it all the time in traffic and it works pretty well. It even steers for you at very low speeds (and yells at you less for not having your hands on the wheel!). Its an assistance system to reduce fatigue, and you still need to pay attention to the world around you.

To answer the question, the popping noise is adaptive cruise activating (or preparing to activate) the real brakes. You only hear it at low speeds due to reduced cabin noise. I have noticed this in other vehicles as well with adaptive cruise, including non-Ford vehicles.

I'm not 100% sure what causes the noise but I suspect you're just hearing the piston in the master cylinder move as it gets ready to use the hydraulic brakes. It's "priming" the brake pedal...though you'll never feel the pedal stiff. The Mach E has an 'all-in-one' Electronic Brake Booster (EBB). It is on the other side of the shaft crossing the firewall and the brake pedal shaft goes directly into it. This is an all in one unit. Hydraulic master cylinder, ABS pump, and brake booster. The brake pedal normally does not create hydraulic pressure to actuate the brakes. The ABS module looks at various data to decide how much hydraulic brake assist is needed then applies the brakes as necessary.

I can't find information on it but in the case of a power failure there is supposed to be a mechanism to directly connect the brake pedal to the master cylinder so you can still stop in an emergency.
 

breeves002

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I have also heard the same sound in my fusion energi and focus electric when the ABS would kick in and it would stop applying regen and apply the full brakes, so I had heard the sound before. I just think the MMEs system is designed slightly differently but I believe it is a normal characteristic and nothing to worry about.
 
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Addos

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Yeah, it is just surprising to someone who has never had a car with adaptive cruise. Before my MME, I was driving a 2009 Ford Focus. So it never had any of this stuff. And when you hear that noise, it sounds like something could be broken or not working right, so I am glad when others can chime in and let me know if everything is ok.

I have also heard the same sound in my fusion energi and focus electric when the ABS would kick in and it would stop applying regen and apply the full brakes, so I had heard the sound before. I just think the MMEs system is designed slightly differently but I believe it is a normal characteristic and nothing to worry about.
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