How does it work the Cruise Control?
08-30-2019, 04:14 PM
#1
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How does it work the Cruise Control?
I know, I know, the question seems a bit silly at first but I would like to know how the cruise control really works behind the scenes, I do not mean how to set, increase, decrease or unset it but rather how the computer does it work. When I have set a given speed and drive down hill the car maintains the speed, I noticed the revs are not specially higher as when I am not using the cruise control and use the engine compression to hold a bit on the speed. A few days back I happened to noticed a car driving behind me close enough to see the reflection of the break lights on while going downhill and having set the Cruise Control, which led me to think the computer was pressing the brakes. I naively thought since the very beginning it was something in the computer telling the engine to hold, but now I am realizing it is actually using the breaks. Am I totally lost on this presumption or do any one agrees/know who can explain in more detail? Thanks in advanced!!!
08-30-2019, 04:56 PM
#2
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1922 Ford Model T / no OBD
This is called "controlled descent" if I remember it right.
When on CC cars rolls down faster than set speed, computer will apply engine brakes (turbo fins on diesels) or it will downshift the gears for better braking. Maybe in critical situation will push the brakes as well, but not sure about it. That triggers brake lights as warning to drivers behind you.
When on CC cars rolls down faster than set speed, computer will apply engine brakes (turbo fins on diesels) or it will downshift the gears for better braking. Maybe in critical situation will push the brakes as well, but not sure about it. That triggers brake lights as warning to drivers behind you.
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ahering (09-03-2019)
08-30-2019, 05:04 PM
#3
Out Of Control!!
I would say that you are close, but no cigar. When you, repeat you apply the break and not an automatic breaking system like the one offered on the W213, the CC is disengaged. All the settings and inputs happen seamlessly within in the ECU map\memory. Inputs include the IC, wheel speed sensors, break light sensor, pedal sensor bla bla.
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ahering (09-03-2019)
09-03-2019, 04:16 PM
#4
Super Member
This is called "controlled descent" if I remember it right.
When on CC cars rolls down faster than set speed, computer will apply engine brakes (turbo fins on diesels) or it will downshift the gears for better braking. Maybe in critical situation will push the brakes as well, but not sure about it. That triggers brake lights as warning to drivers behind you.
When on CC cars rolls down faster than set speed, computer will apply engine brakes (turbo fins on diesels) or it will downshift the gears for better braking. Maybe in critical situation will push the brakes as well, but not sure about it. That triggers brake lights as warning to drivers behind you.
09-27-2019, 01:43 PM
#5
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'71 Pinto
Basic functions...
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ahering (09-27-2019)
