Cruise Control

[Freddo]

Does anyones cruise control not work when going down hill?

is that normal?

[DJKOR]

Mine still works while going downhill. It pretty much cuts the throttle as I go downhill, but thanks to the laws of gravity, the car will pick up speed depending on hill. If I do not touch the brakes, when I get back on level ground, it will coast until set speed is reached and then continue to maintain speed. This I see as cruise control doing it's job.

If I hit the brakes however to avoid accelerating over the limit, then cruise control turns off as per it's design.

[lateralus]

daryl is 100% correct. some manufacturers, such as lexus, do have a feature that lightly applies the brakes automatically once your speed exceeds the cruise control setting, the same way the throttle is applied when your speed decreases from the desired setting. unfortunately, toyota's dont have that (well, not yet anyway)

but daryl, its interesting you say our car cuts the throttle going down hill. in slight hills, mine is still applied very slightly and i have to cancel the setting to let it coast down then reset it once the roads flat again. but on steep hills, obviously it cuts out once it realises what its doing

Edited October 7, 2009 by lateralus

[Steven]

actually the Aurions do drop down a gear to try and stop the car accelerating too much on slopes. It doesn't make a huge difference but you can easily feel it.

[PaulMT]

Does anyones cruise control not work when going down hill?

is that normal?

I use cruise control a lot and I can certainly say it holds going down hill as good as any cruise control I have ever had.

The car will gather some momentum due to gravity but if you haven't got cruise set close to the speed limit it will keep you within the limit.

[WildfireATX]

Is it really that hard to use a brake pedal? i know cruise control is good but seriously you want to be so lazy you want to rely on it to even slow you down now? come on!!!

side note: gf never had a car with cruise b4 aurion and when she used it first time and went up hill and it kicked down a gear she had well lets just say "a moment" where pure panic crossed her face and she thought god the cars going to kill us hilarious.

[Wulfkind]

Is it really that hard to use a brake pedal? i know cruise control is good but seriously you want to be so lazy you want to rely on it to even slow you down now? come on!!!

side note: gf never had a car with cruise b4 aurion and when she used it first time and went up hill and it kicked down a gear she had well lets just say "a moment" where pure panic crossed her face and she thought god the cars going to kill us hilarious.

I find going down hill that the car usually will engine brake sufficiently to stop you from going more than 10kph over your set speed... I don't mind the way it works. That said, cruise control really is designed for flat, straight roads... Use your brake if you don't want to speed.... CC is very easy to reenable at your desired speed anyhow.

[Woodsie]

I just got back from a holiday where we drove from Mt Isa to Bundaberg to Townsville to Mt Isa about 4k km's. The Aurions cruise did as Steven said if the speed was getting away and reduced throttle couldn't hold the set speed it would drop down a gear to help.

What I think would help more than braking to hold set speed is a system that would allow you to set a speed but when you catch up with slow traffic hold you at the slower speed till you make your passing maneuver.

[Freddo]

yeah i am lazy hence i bought an aurion which is an AUTOMATIC car lol.

im asking because i cant remember if its the same in other cars... i thought it kept it on the set speed even on declines...

one of the major points of having cruise control is to set it to a speed under the speed limit?

when u depress the brake it cancels the cruise control!

so yeh im lazy...

and what is the point of having cruise control if it doesnt work all the time?

lol

Edited October 10, 2009 by Freddo

[marc2020]

I use the cruise control to keep within the speed limit on long drives. Car cruises far too smoothly at speeds way above 100km/h, too easy to sit at 120+ without realising it. But I have noticed the same thing as the others, while going down hill the car will engine brake to keep within the set speed.

[dave262]

but daryl, its interesting you say our car cuts the throttle going down hill. in slight hills, mine is still applied very slightly and i have to cancel the setting to let it coast down then reset it once the roads flat again. but on steep hills, obviously it cuts out once it realises what its doing

Mine is the same as this too - I've had it downhill on a freeway get as high as about 130 and it still hadn't dropped down a gear or anything... if anything it still has very slight throttle too. Problem with the Aurion though is that at 130 the car still feels so smooth, that you don't notice till looking at the speedo!

[Freddo]

but daryl, its interesting you say our car cuts the throttle going down hill. in slight hills, mine is still applied very slightly and i have to cancel the setting to let it coast down then reset it once the roads flat again. but on steep hills, obviously it cuts out once it realises what its doing

Mine is the same as this too - I've had it downhill on a freeway get as high as about 130 and it still hadn't dropped down a gear or anything... if anything it still has very slight throttle too. Problem with the Aurion though is that at 130 the car still feels so smooth, that you don't notice till looking at the speedo!

yeh thats my problem... you get so comfortable u dont look at the speedo and next minute ur like over the speed limit.

esp the suspension in the presara.

[DJKOR]

im asking because i cant remember if its the same in other cars... i thought it kept it on the set speed even on declines...

Cruise control on most other cars is just the same in which the throttle is the only thing that is controlled.

one of the major points of having cruise control is to set it to a speed under the speed limit?

It's main purpose is for, you guessed it.... cruising. Mainly for highways so your foot doesn't go dead on you.

when u depress the brake it cancels the cruise control!

That's called a safety feature. It's so you don't accelerate again and create an accident.

so yeh im lazy...

and what is the point of having cruise control if it doesnt work all the time?

I'm guessing you are disappointed that it can't steer the car as well :P

[m_luke]

The cruise control system as fitted in our cars (Gen5, Gen5.5, Gen6 and Gen6.5 Camry/Aurions) are all basic speed control systems that work perfectly well on flat roads.

On uphill roads, depending on gradient and torque output of the engine, it will force the transmission to downshift if it senses that it is not keeping up with the set cruise speed, which if you are not expecting the downshift action may cause a slight panic moment for the driver. This is particularly the case with the 4cyl models where a surging effect can be felt when travelling over minor undulations with cruise control set because it is unable to maintain the set constant speed.

On downhill roads, as described in a previous post, the cruise control does nothing except cut all throttle input. For Gen5 and Gen5.5, because the throttle is controlled by throttle cable and part of the cruise control system consists of a mechanical device daisy-chained onto the cable, the device simply releases the throttle cable to a point that it believes is zero throttle input, but in fact there is still a tiny amount of throttle input being registered hence one can still feel throttle input.

This is probably one reason why Gen6 and beyond switched to drive-by-wire technology where zero throttle input actually means zero throttle input.

The cruise control systems where brakes are applied on downhill roads are actually called Active Cruise Control systems where the it can instruct the braking system to apply the brakes; Merc S Class and high end Lexus technology.

Previous posts also mentioned the experience of a 'speed hold' function when the car is travelling downhill. This is completely separate of the cruise control system and is actually a function of the auto transmission as fitted to Gen6 Camry/Aurion and beyond and is something that Toyota Japan have fitted to a lot of their auto transmission cars, I think, 2 generations ago.

-m_luke