Adaptive Cruise Control braking

[hybridbear]

In the black FFH I would use the cruise quite often on certain stretches of common routes through the city. On certain downhills I would turn on the Hill Descent Control because Eco Cruise would allow me to gain more speed than I was comfortable with. Driving the white FFH today I found that I didn't need to turn on the hill descent control because the car braked and the spinning regen symbol appeared on the display when going down the hill. Using Hill Descent Control the spinning regen symbol wouldn't appear, but the effect was the same as stepping on the brake pedal.

 

Have others with Adaptive Cruise experienced this? Is this normal? It seems so strange to me that Adaptive Cruise would brake on downhills and regular cruise control wouldn't...

[gkinla]

I had a 2010 FFH and the regular cruse control would allow the car to continue to accelerate on steep down hills. The 2013 FFH with Adaptive Cruise Control brakes the car on steep decent, with or without Eco Cruise on. I like this feature, although the cars following tend to creep up to my rear bumper. The earlier cruise control was just a throttle body control. After the throttle plate was fully closed and the hill was steep enough to overcome engine braking, gravity would take over and accelerate the car.

Edited December 2, 2013 by gkinla

[DeeCee]

With ACC on I see regen braking going down hills all the time. Seems to be normal. If the hill is steep enough the regular brakes may also be applied to hold the speed down.

[Waldo]

The ACC module has the brake control module on speed dial. Conventional cruise is all inside the PCM and not tied into the brake system. This is the case on all Ford ACC systems, not just the hybrids.

[Toz]

in fact for the non-hybrids the manual recommends that you turn off the ACC when going down steep grades as to not overheat the brakes.

[acdii]

My F150 would brake going downhill while cruise was on. It didnt have ACC. At least it felt like it was braking and the brake lights came on going down the mountain in CO.

 

Oh my Flex brakes too with ACC.

Edited December 2, 2013 by acdii

[Waldo]

My F150 would brake going downhill while cruise was on. It didnt have ACC. At least it felt like it was braking and the brake lights came on going down the mountain in CO.

 

 

I don't believe it. From the 2012 F-150 shop manual:

 

The inputs to the PCM are:

• Output Shaft Speed (OSS) sensor
• Digital Transmission Range (TR) sensor
• Cruise control switch(es) (networked from SCCM )
• Cruise control deactivator switch (integral to the stoplamp switch)
• Stoplamp switch
• Accelerator Pedal Position (APP) sensor
• Vehicle speed (networked from ABS module)

The outputs of the PCM are:

• Cruise control indicator lamp request to the IPC
• Throttle body

The vehicle speed is controlled by the PCM through the Electronic Throttle Control (ETC) subsystem.

 

No mention of the brake output at all.

[acdii]

Like I said, I dont know if the actual brakes applied, all I know is my tail was lighting up the road behind me going down that mountain, and my feet were flat on the floor. It held the speed limit set on CC all the way up and down. I was quite impressed with it too.

[hybridbear]

This is how Ford should be marketing the Fusion & its advanced driver assistance technologies!

http://www.motorauthority.com/news/1093086_drivers-leap-from-moving-cars-to-test-hyundai-genesis-safety-system-video

 

http://youtu.be/EPTIXldrq3Q

 

I'd like to see a future enhancement to Ford's Adaptive Cruise Control system allow it to bring the car fully to a stop like the Hyundai in the video.

Edited July 30, 2014 by hybridbear

[darrelld]

The adaptive cruise control does apply the brakes. I have tested this but it does seem to wait a bit too long before actively braking. I haven't found a way to adjust the behavior yet.

[hybridbear]

The adaptive cruise control does apply the brakes. I have tested this but it does seem to wait a bit too long before actively braking. I haven't found a way to adjust the behavior yet.

I agree that it waits too long. Even the longest distance setting is too close for me.

 

The only thing you can do is adjust your following distance setting.

 

The other thing I don't like is that it will detect a car when it's much farther out than just matching it's speed at 4 bars. But if that vehicle is going 60 MPH & I'm doing 65 it doesn't gradually slow me down to 60. It will keep doing 65 even though it knows there's a car in front then it will suddenly brake to slow me down to 60. I don't like that.

 

I also wish it would give you some type of warning before braking. I usually can judge the closing distance & change lanes before it would start slowing me down when on open freeway but in the city sometimes I wouldn't realize that the car that was doing 65 in front of me is now doing on 60 until I look down at the speedometer. I wish it would alert you when it's slowing you down because of an object in front. The symbol that it detects an object in front doesn't mean it's slowing you down.

[Easy Rider]

It will keep doing 65 even though it knows there's a car in front then it will suddenly brake to slow me down to 60. I don't like that.

 

 

My '14 does not do that.

It slowly matches speeds.

I have not yet had an instance where it applied the brakes.

I have not, however, tested that at the minimum following distance.......and probably won't, as I think being that close should preclude having the cruise set.

[acdii]

The adaptive cruise control does apply the brakes. I have tested this but it does seem to wait a bit too long before actively braking. I haven't found a way to adjust the behavior yet.

It's field of view is skewed though. I use cruise between my office and my wifes due to the hills, and when I see a car turning, I hit cancel and as it clears the lane I hit resume, and sometimes it will still detect the car as in my lane and hit the brakes, Hits it hard too. By keeping a toe on the gas it overrides the cruise though so hitting resume when you know the car will clear will prevent the brakes from coming on.

[darrelld]

It's field of view is skewed though. I use cruise between my office and my wifes due to the hills, and when I see a car turning, I hit cancel and as it clears the lane I hit resume, and sometimes it will still detect the car as in my lane and hit the brakes, Hits it hard too. By keeping a toe on the gas it overrides the cruise though so hitting resume when you know the car will clear will prevent the brakes from coming on.

 

I have noticed this with the Collision Avoidance Warning too.