Cruise Control Automatic Braking

[Drew Toner]

Don't believe everything that AI says.

I understand sir, but it was still informative!!

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[PltFX4]

Don't believe everything that AI says.

Nonsense... but be selective.... I have caught it making mistakes, but it can/has scanned more doucments that any of use have common access to and does a better than average job of summerizing them.

 

[RangerBill]

Nonsense... but be selective.... I have caught it making mistakes, but it can/has scanned more doucments that any of use have common access to and does a better than average job of summerizing them.

If you have to be selective on what you believe that AI is telling you, then my statement "Don't believe everything that AI says" is correct, not nonsense. Your AI generated report is telling the OP that his brake lights should be coming on when the Cruise Control is keeping the truck from gaining speed above his setpoint going downhill. You stated that he has an issue with his brake lights because he stated that they didn't come on during the above circumstances. I don't think that that is a problem with his truck, in my opinion. His speed is not changing, so it would make sense that the brake light wouldn't come on to confuse drivers behind him. I have no firsthand knowledge of this, but the OP has tested the situation and said that the brake lights didn't come on.

 

[Drew Toner]

If you have to be selective on what you believe that AI is telling you, then my statement "Don't believe everything that AI says" is correct, not nonsense. Your AI generated report is telling the OP that his brake lights should be coming on when the Cruise Control is keeping the truck from gaining speed above his setpoint going downhill. You stated that he has an issue with his brake lights because he stated that they didn't come on during the above circumstances. I don't think that that is a problem with his truck, in my opinion. His speed is not changing, so it would make sense that the brake light wouldn't come on to confuse drivers behind him. I have no firsthand knowledge of this, but the OP has tested the situation and said that the brake lights didn't come on.

Maybe a schematic guy can tell us when the brake lights should coming on.
I'm only curious because I have had the acc bring me to a full stop, and am just wondering if the people following can see any brake lights?

 

[RangerBill]

Maybe a schematic guy can tell us when the brake lights should coming on.
I'm only curious because I have had the acc bring me to a full stop, and am just wondering if the people following can see any brake lights?

Yes, they should come on since you are slowing to a stop. Schematic diagrams won't answer that question since it would be determined by the cruise control system programming.

 

[RangerBill]

Maybe a schematic guy can tell us when the brake lights should coming on.
I'm only curious because I have had the acc bring me to a full stop, and am just wondering if the people following can see any brake lights?

Also, during AEB (automatic emergency braking events) the truck will cause the brake lights to illuminate, so I would say that they illuminate if the cruise control slows the truck. In your case above, it may have been AEB that stopped your truck as I am not sure our 5G Rangers ACC will completely stop our trucks in traffic as the 6G Rangers I believe do.

 

[Drew Toner]

Also, during AEB (automatic emergency braking events) the truck will cause the brake lights to illuminate, so I would say that they illuminate if the cruise control slows the truck. In your case above, it may have been AEB that stopped your truck as I am not sure our 5G Rangers ACC will completely stop our trucks in traffic as the 6G Rangers I believe do.

OK, good to know!

 

[Jason B]

Maybe a schematic guy can tell us when the brake lights should coming on.
I'm only curious because I have had the acc bring me to a full stop, and am just wondering if the people following can see any brake lights?

That's not the ACC, that's the Collision Avoidance doing that. That happens whether or not you have ACC on. Happened to me a few times, and my STX didn't have Auto Cruise Control.

 

[PltFX4]

If you have to be selective on what you believe that AI is telling you, then my statement "Don't believe everything that AI says" is correct, not nonsense. Your AI generated report is telling the OP that his brake lights should be coming on when the Cruise Control is keeping the truck from gaining speed above his setpoint going downhill. You stated that he has an issue with his brake lights because he stated that they didn't come on during the above circumstances. I don't think that that is a problem with his truck, in my opinion. His speed is not changing, so it would make sense that the brake light wouldn't come on to confuse drivers behind him. I have no firsthand knowledge of this, but the OP has tested the situation and said that the brake lights didn't come on.

I don't believe what anyone, let alone AI, says on face value without evaluating the what credibly they have on the topic... so why would AI be any different?

What I said was, based on what he discribed (and he did not say which senario was active when his wife saw no brake lights), IF when in ACC mode and the ABS was applying the brakes (and not just slowing because of engine torque), and the lights were NOT coming on, then there was something not working as it should... ie: broken.

 

[airline tech]

You will know if (AEB) triggered the braking - the - ALERT - will startle you, in fact recently - the alert triggered (alert only) but I was already on the brakes - DEER - I will say - the truck has proven to me on more than 1 occasion - it will stop on a dime.
The Alert - is a 3 Tone Chime and it is loud
I know there is a (RED) alert and something about collision (I think Pre-Collision) - my eyes are always focused on the road - I have never had the (AEB) trigger but I suspect it would be the same warning plus actual braking.

Now with that - and factoring in other times brake pressure is applied automatically
1. Traction / Stability Control
2. Trail Control - Hill Control etc
2. ACC / CC

We can see that the ABS Module (itself) is the decision maker on Brake Pressure (applied)

Note:
Stop lamp Request = is normal brake pedal applied - message
Stop lamp brake request - (originates from the ABS Module)

So I read this as - if the ABS module - commands brake pressure it triggers the brake lights to illuminate.

The (MISSING INFORMATION) is what brake pressure and or brake pressure applied (time) will trigger the message to be sent.
This may be the reason that some are reporting (brake lights did not come on) and someone following confirmed it.
What has not been (provided) or stated is a confirmation that it was actually applying the brakes or a hard downshift (engine braking) and if applying the brakes, how much of a braking event was occurring - (subtle light pressure or hard pressure)

I am guessing that this messuage is for - AEB

Basically - we have the manual description / owners manual description - plus (online) searches all overlapping without any clear data.

The only true way to see what is happening behind the scenes is to perform a live data drive and monitor the - Cruise Control PIDs and the Stop Lamp / Emergency Stop Lamp PIDs and introduce various (driving) parameters another good thing to add would be (forced gear shift) PID - this would be the downshift and the PID reading of the Brake Pressure, this would show what is actually slowing the truck down.

Normal
Normal - Slow Moving Vehicle (In Front)
Tailgate (Testing) - how does it react if come up quickly on a slow moving vehicle
Down Hill (coast) control

Summary - for me - it all ties into the brake pressure itself and the duration of the brake pressure and since there is not a clear answer for should the brake lights illuminate with ACC/CC as we can confirm that they do with (AEB) - this is the reason the (Ford Branded) TBC was required - (Picks Up the CHMSL) signal that brakes are applied.
Then we need to perform a live data drive to see behind the scenes.

Sorry, I do not have a clear answer to this question but it makes the most logical sense to me - that the Brake Pressure + Duration (Applied) Pressure - is what triggers the stop lamp request message via ABS braking control events.

 

[Drew Toner]

[QUOTE="

Sorry, I do not have a clear answer to this question but it makes the most logical sense to me - that the Brake Pressure + Duration (Applied) Pressure - is what triggers the stop lamp request message via ABS braking control events.
[/QUOTE]

And this all makes sense to me. If I'm just descending down hill, or following a slower vehicle, maybe the brake lights don't come on. But if I get into a fast, hard deceleration, then my brake lights better come on!!

And yes, I once did see the red box warning, and hear the chimes. My acc was just starting to resume speed, after a slower vehicle moved out of my lane, when seconds later, another vehicle moved in front of me. I saw it all take place, and was prepared, but the truck wasn't happy!!

 

[airline tech]

Did some digging and I was close but not 100% on the mark.
Its not the - Brake Pressure that determines - Stop Lamp (Illumination) it's the decarceration rate that is reported by the (RCM -Restraint Control Module) the RCM holds the accelerometers and gyros.

So small brake applications (via ABS Control) will not generate a brake light, but a more aggressive brake application will, it mainly depends on how fast the decarceration rate is.

 

[Drew Toner]

Did some digging and I was close but not 100% on the mark.
Its not the - Brake Pressure that determines - Stop Lamp (Illumination) it's the decarceration rate that is reported by the (RCM -Restraint Control Module) the RCM holds the accelerometers and gyros.

So small brake applications (via ABS Control) will not generate a brake light, but a more aggressive brake application will, it mainly depends on how fast the decarceration rate is.

So, now we know the rest of the story!! Good sleuthing sir!!

 

[got3fords]

Did some digging and I was close but not 100% on the mark.
Its not the - Brake Pressure that determines - Stop Lamp (Illumination) it's the decarceration rate that is reported by the (RCM -Restraint Control Module) the RCM holds the accelerometers and gyros.

So small brake applications (via ABS Control) will not generate a brake light, but a more aggressive brake application will, it mainly depends on how fast the decarceration rate is.

How did this turn to jails?
" Decarceration is the policy and practice of reducing the number of people held in prisons and jails, serving as the direct opposite of incarceration. It encompasses strategies to divert individuals from entering the carceral system through decriminalization, bail reform, and alternative sentencing, as well as releasing those currently incarcerated via expanded parole, sentence reductions, and early release programs."

 

[Drew Toner]

How did this turn to jails?
" Decarceration is the policy and practice of reducing the number of people held in prisons and jails, serving as the direct opposite of incarceration. It encompasses strategies to divert individuals from entering the carceral system through decriminalization, bail reform, and alternative sentencing, as well as releasing those currently incarcerated via expanded parole, sentence reductions, and early release programs."

I saw that to, but I 'assumed' that he didn't mean that!!

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