HELP: HIGH RPM & slow speed while driving Downhill

[mpitts1]

I haven't had time to read everything posted here, but how do you switch to "constant speed" mode? My 2017 Corolla LE w/ eco mode increases to 4200 rpm on every downhill, and I'm afraid it would get only worse with steeper descents.

I posted previously that my cruise canceled itself out, which now I don't think that's the case. I haven't duplicated this problem enough times to have a strong opinion on it.

Also, thanks DJ G_Roc. Something didn't sound right about what the service guy said. Sadly, I'm not surprised.

I'll keep checking in on this thread, and thanks, jolly, for the good info.

I haven't had time to read everything posted here, but how do you switch to "constant speed" mode? My 2017 Corolla LE w/ eco mode increases to 4200 rpm on every downhill, and I'm afraid it would get only worse with steeper descents.

I posted previously that my cruise canceled itself out, which now I don't think that's the case. I haven't duplicated this problem enough times to have a strong opinion on it.

Also, thanks DJ G_Roc. Something didn't sound right about what the service guy said. Sadly, I'm not surprised.

I'll keep checking in on this thread, and thanks, jolly, for the good info.[/QUOT

I haven't had time to read everything posted here, but how do you switch to "constant speed" mode? My 2017 Corolla LE w/ eco mode increases to 4200 rpm on every downhill, and I'm afraid it would get only worse with steeper descents.

I posted previously that my cruise canceled itself out, which now I don't think that's the case. I haven't duplicated this problem enough times to have a strong opinion on it.

Also, thanks DJ G_Roc. Something didn't sound right about what the service guy said. Sadly, I'm not surprised.

I'll keep checking in on this thread, and thanks, jolly, for the good info.

Well drequeen if you have read my previous posts, you know that my problem was about as bad as it gets. Then jolly told me how to put the cruise control into "constant speed mode". So I grabbed my owners manual and followed what he had described exactly. With the cruise control OFF, press the button to turn on the cruise control at about the speed you want to set it. Keep the button depressed, and when it is first depressed you get the display saying that the radar mode is ready, that is where we have been making the mistake, and setting our speed with the radar mode on. Keeping the button depressed for 2.5 seconds switches it to the constant speed mode, then just set your speed where you want it. That is what I tested on my drive home from work on Sunday. Thirty five miles later, not once did my rpm's go over the level they were on level ground, except for a minor increase as I went on the upside of an overpass. On the downside of the overpass, where I was experiencing those spikes of over 5000 rpm's, they stayed put. As I commented, I did not have the opportunity to try and tweak the dynamic radar cruise control's following distance from long, to medium, or short, to see if that would yield a better result on the radar mode. I will do that on Friday at 05:00. This info from jolly, who I will continue to thank again, along with reading my owners manual, has proven to be a godsend to me. I thought how in the hell will this cruise control ever save me on gas, or give me the respite that I needed, or wanted, from my foot on the accelerator. I was having to tap the accelerator to stop the revving every single time I went over an overpass. I hope this helps you as well. I will post again after my trip to work explaining the results of my further tweaks.

 

[jolly]

Glad that "constant" mode works fine. That still leaves the problem on "radar" mode though. Maybe longer distance setting would help but any mode should work OK (you paid for it !)
I still suspect radar being confused by hitting either road at an angle, oncoming traffic or even road signs, and triggering extra engine braking (which - to a point ! - is to be expected from a CVT.)
At least the experiment seems to rule out the cruise itself and the Toyota/Aisin CVT, which, again, has been in Corolla for years and, by any reviewer number, is "faster" and more efficient than the old 4AT.
Whatever it is, you'll now be able to describe the problem in a more specific way to a mechanic. Firmware glitch on "radar" ? Some faulty sensor ? Who knows !

Remember, for the cruise :
(From off position) : press = "radar" cruise / press and hold = "constant" speed
Also, you don't necessarily have to use the pedals to disengage cruise : just pull the lever towards you (and up to resume).
Knowing if this works properly when engine is over revving might also help to pinpoint the problem.

 

[drequeen]

I'll have to try it tomorrow. I'm almost certain I had it in constant speed mode coming home from work, but I'll keep fiddling with it. Other than that, the new Corollas are awesome, such a fun car to drive.

 

[Aneef]

GUYS!

I recently bought a 1.8L Corolla Altis Cruisetronic with 7-Speed CVT Transmission (European/Asian Version). The car comes with P, R , N, D, and an M (+ and -) mode that supports 7-speed sequential shifting. Please guide me on how to do engine braking to keep the car speed under 35 km/h when going downhill. Do I need to keep my car in D mode (Drive mode) or should I switch to M mode and keep my car in 1st or 2nd gear?
If I keep my car in D mode, would the car increase its speed automatically when going downhill if I don't press the gas pedal? Or would it provide the engine braking to slow down the car? I have never drove CVT before, and just completed 1000 kms inside my City and now I plan to visit some hill station so I need to know these details.

Thanks a lot.
Greetings from Pakistan

 

[DJ G-Roc]

GUYS!

I recently bought a 1.8L Corolla Altis Cruisetronic with 7-Speed CVT Transmission (European/Asian Version). The car comes with P, R , N, D, and an M (+ and -) mode that supports 7-speed sequential shifting. Please guide me on how to do engine braking to keep the car speed under 35 km/h when going downhill. Do I need to keep my car in D mode (Drive mode) or should I switch to M mode and keep my car in 1st or 2nd gear?
If I keep my car in D mode, would the car increase its speed automatically when going downhill if I don't press the gas pedal? Or would it provide the engine braking to slow down the car? I have never drove CVT before, and just completed 1000 kms inside my City and now I plan to visit some hill station so I need to know these details.

Thanks a lot.
Greetings from Pakistan

You have to switch it to manual shift mode in order to downshift to a lower gear & make it stay there.

 

[mpitts1]

Glad that "constant" mode works fine. That still leaves the problem on "radar" mode though. Maybe longer distance setting would help but any mode should work OK (you paid for it !)
I still suspect radar being confused by hitting either road at an angle, oncoming traffic or even road signs, and triggering extra engine braking (which - to a point ! - is to be expected from a CVT.)
At least the experiment seems to rule out the cruise itself and the Toyota/Aisin CVT, which, again, has been in Corolla for years and, by any reviewer number, is "faster" and more efficient than the old 4AT.
Whatever it is, you'll now be able to describe the problem in a more specific way to a mechanic. Firmware glitch on "radar" ? Some faulty sensor ? Who knows !

Remember, for the cruise :
(From off position) : press = "radar" cruise / press and hold = "constant" speed
Also, you don't necessarily have to use the pedals to disengage cruise : just pull the lever towards you (and up to resume).
Knowing if this works properly when engine is over revving might also help to pinpoint the problem.

Well I tested the radar mode the last couple of days, and I am still perplexed. When set on all following distances, it seems to operate about the same. Sometimes it goes down the other side of the overpass without an increase in rpm's, and sometimes it goes up to over 4000 rpm's, and it does this in regular, and sport mode. It will sometimes go over four or five overpasses without a spike of the rpm's, only to suddenly return on the next similar overpass. This occurs even at 05:15 when I am the only car on the highway that I am driving, and also during times of normal traffic. This is in all of the following distances, short, medium, and long. It is however not as bad as it was the first time I used the radar cruise control mode. That is when it spiked to 5400 rpm's. I think I will keep using my constant speed mode, as it performs just fine. As for the service department manager, I was not able to go in again due to my work. We are in a busy time right now, and I have had to come into work, forcing me to cancel the repair of my window tinting. That's a completely different problem that I am very ticked off about, but that's another thread.

 

[Jason Andrus]

I have a new Toyota Corolla (Automatic Gear & mileage around 2900 kms only) bought in May 2015 from Toyota Mauritius.

I would like to officially report, with concern, a mechanical problem that I have faced twice on 16 July 2015 which could have resulted in serious consequences.

Occurence 1:
While driving down a steep inclined road in "D" gear and decelerating, the car slowed down abruptly by itself with the engine revolutions per minute (RPM) rising up to 4000+. The car could not be driven normally as it was moving very slowly at very high RPM. I had to stop and switch off the engine. On resuming the engine, the car returned to its normal state and I could drive further on subsequent lesser inclined roads. (You may wish to note that during normal driving conditions, the RPM hardly reaches the 3000 mark).

Occurence 2:
Some minutes later during another steep descent, the same problem happened but this time the RPM went up to 5000+. I had to brake completely to a halt and then only, the car returned to its normal state.

Even if the car responds normally on most cases, I fear that the above mentioned problem puts the safety of passengers into risk as such occurrences could repeat itself during steep descents and could lead into serious issues if there are traffic behind the car.

I would be grateful if anybody could share if they have ever encountered the above or have a solution to this issue. Thank you.

You're correct that is an issue and isn't normal, you should be in control of your car slowing, you can manually do it by shifting down the lever but it shouldn't be automatic. If it happens again throw it in neutral

 

[Murphy cat]

CVT transmission just like this .the same as me . normal.not worried.

 

[skippy1959]

I looked at my brochure, 2017 has the CVTi-S transmission. They called it i for intelligence. My rev's up no matter if in dynamic cruise or normal cruise mood. No difference if i change the setting to close, mid or far on dynamic cruise info screen. I have not heard back from the NHSTA, but on the initial email stated could be 90 days before i did hear back. Since its not a death issue, they don't jump on it right away is my guess.

 

[drequeen]

Hey guys, been a while. I'm on my 2nd 2017 Corolla, and it's the same with both. As skippy1959 posted, it revs up in either mode (the stupid dealer sold me the wrong Corolla. The one with the correct VIN # was coming in on a shipment. No bother, I got a free tank of gas and 800 or so miles wiped off).

I basically don't use cruise anymore. On any downhill, it revs to over 4,000 rpm, which is absolutely ridiculous. I've a lot of other things going on now, so I don't have time to mess with this, but I will check in from time to time. At my 5,000 mile service, I will certainly bring it up, and voice my displeasure.

 

[Yvon Lemire]

I have a new Toyota Corolla 2017 LE (CVT).
I was using cruise control, the rpm was about 1500, while driving down an inclined road in "D" gear, the revolution of the motor increased suddenly to about 4000+ rpm. After the inclination, the rpm would drop back down to normal. It was very surprising. I understand that the cruise control maintains a constant speed, but I consider it is not normal to use this high revolution of the motor to brake the car. I am concerned by the noise of that, this will affect the reliability of the motor and the CVT. It is not my first car with cruise control and it is the first time I notice this method. I want that someone give me a solution to avoid this. The only way that I used is to put the cruise control «off» when I see an inclined road and put it «on» when it is a flat road. I hope to find a better way to solve this problem.

 

[Chris Denton]

It's downshifting, attempting to maintain the speed your set to.

 

[jolly]

I am concerned by the noise of that, this will affect the reliability of the motor and the CVT. It is not my first car with cruise control and it is the first time I notice this method. I want that someone give me a solution to avoid this. The only way that I used is to put the cruise control «off» when I see an inclined road and put it «on» when it is a flat road. I hope to find a better way to solve this problem.

It's engine braking, CVT way. Not a defect. The only solution is what you mention : cancel the cruise (it's just a tap to cancel, another one to resume). Plus don't use radar function on hilly roads, as it can be "fooled" by that. Actually, the OM don't even recommend using the cruise on hilly drives.

 

[Rylee]

I've had this happen when using cruise control and going downhill. The CVT downshifts automatically to slow the car down. This is normal, but if you don't like it just tap on the gas pedal to resume the normal gearing.

Good to know my car does the same thing! Thanks man!

 

[Kevin Burghart]

Hi Everyone, new to the forums here. I bought a 2017 Corolla Le last December. I am having issues with the engine revving while going down hill. The cruise control is not on, I am just coasting down a hill and the engine revs up to 3000 rpm. It doesn't do it every time, just sporadically. It has been doing it for about 6 months.
It is at the dealer right now. I doubt they will be able to replicate the issue. Anyone else experience this with out the cruise control?

 

[Chris Denton]

Sounds like you have an automatic with a CVT transmission?
Mine did this too when it was new but has gone away now.
I’m pretty sure it’s normal for our cars to do this.

 

[klebinek]

What happens if you hit the breaks, does it override engine breaking resulting in RPMs going back to normal? This has never happened to me but I live in the flat Midwest Chicago area. I would like to experience this or see this on video, is this violent to the point where you're being grabbed by your seatbelts or the fact that the engine starts being very loud unexpectedly makes it appear worse then it actually is? Personally I think there are better options that can be utilized fairly cheap and put power back into the battery even though it's not a hybrid as opposed to having the engine do the breaking. How come Mazda was able to incorporate regenerative breaking on some if not all of their new skyactive (non-hybrid) cars? How come Mazda 3 or 6 was able to achieve better mpg using traditional 6 speed auto tranny which they've perfected and you can bet there won't be any issues with it.

And here we have a corolla with some damn CVT which less enjoyable, reliable, serviceable than Mazda...

I'm a computer engineer by trade and often times when falling asleep I think about these solutions that are right there but for whatever reason some automakers chose to make these dumb decisions when the answer is right there. Let's take regen breaking, I think it's an marvelous idea and how much more would a corolla cost with that technology? One or two thou if that, I would pay considering your brakes would probably last lifetime of the vehicle which is very cost effective.

 

[jolly]

How come Mazda was able to incorporate regenerative breaking on some if not all of their new skyactive (non-hybrid) cars? How come Mazda 3 or 6 was able to achieve better mpg using traditional 6 speed auto tranny which they've perfected and you can bet there won't be any issues with it. And here we have a corolla with some damn CVT which less enjoyable, reliable, serviceable than Mazda...

It would indeed be nice to have more of those efficient technologies combined in one car. The closest you get is Tesla, which shows that it has a price… On Mazda3, i-ELOOP was an $800 option, available only on higher-end 3, driving the priceclose to $30K. “Was”, because it’s been dropped, partly for documented early issues but mostly because at this price point, consumers have other models in mind.

i-ELOOP was a 1 MPG gain (EPA). By comparison, the CVT vs 4AT in Corolla was a 3 MPG (EPA) gain (with slightly better acceleration numbers, despite what some perceive because of the way it operates). The $800 Valvematic option can add another 2 MPG.

While it’s remarkable that Mazda achieve about the same MPG as Corolla with more power, Corolla has a different target: low cost basic yet satisfying transportation. Not much appeal for so called “enthusiasts” but the definition of “enjoyable” is really subjective.

As far as being serviceable, Mazda ATs are of the “sealed” type like most if not all current ATs/CVTs. Reliability wise, no data suggest a huge difference. You’ll find some complaints on Corolla forums… and some on Mazda forums. Frequency of transmission issues among reported repairs are, according to TrueDelta : 6% for Corolla, 7% for 3 and 9% for 6. Not significant.

While we’ve recently seen a TSB regarding an ECU update (not a transmission swap) potentially needed in some Corolla’s unit, you’ll also find TSB regarding Mazda 6AT (keeping in mind that TSBs are merely technical info for mechanics, not recalls or spreaded problems, and that no engineering execution is always absolutely perfect):
TSB ID: 05-002-17-3355a - The shifter may jump out of 3rd gear over a road bump when accelerating after deceleration
TSB ID: 05-002-15-3019E - Check engine light and automatic transaxle warning light on with one or more of these dtcs

On the main subject of this thread, beside the possible unit defect, heavy engine braking is a characteristic of most modern AT/CVTs that seem to confuse a lot of drivers. Just visit forums from other brands!

 

[klebinek]

It would indeed be nice to have more of those efficient technologies combined in one car. The closest you get is Tesla, which shows that it has a price… On Mazda3, i-ELOOP was an $800 option, available only on higher-end 3, driving the priceclose to $30K. “Was”, because it’s been dropped, partly for documented early issues but mostly because at this price point, consumers have other models in mind.

i-ELOOP was a 1 MPG gain (EPA). By comparison, the CVT vs 4AT in Corolla was a 3 MPG (EPA) gain (with slightly better acceleration numbers, despite what some perceive because of the way it operates). The $800 Valvematic option can add another 2 MPG.

While it’s remarkable that Mazda achieve about the same MPG as Corolla with more power, Corolla has a different target: low cost basic yet satisfying transportation. Not much appeal for so called “enthusiasts” but the definition of “enjoyable” is really subjective.

As far as being serviceable, Mazda ATs are of the “sealed” type like most if not all current ATs/CVTs. Reliability wise, no data suggest a huge difference. You’ll find some complaints on Corolla forums… and some on Mazda forums. Frequency of transmission issues among reported repairs are, according to TrueDelta : 6% for Corolla, 7% for 3 and 9% for 6. Not significant.

While we’ve recently seen a TSB regarding an ECU update (not a transmission swap) potentially needed in some Corolla’s unit, you’ll also find TSB regarding Mazda 6AT (keeping in mind that TSBs are merely technical info for mechanics, not recalls or spreaded problems, and that no engineering execution is always absolutely perfect):
TSB ID: 05-002-17-3355a - The shifter may jump out of 3rd gear over a road bump when accelerating after deceleration
TSB ID: 05-002-15-3019E - Check engine light and automatic transaxle warning light on with one or more of these dtcs

On the main subject of this thread, beside the possible unit defect, heavy engine braking is a characteristic of most modern AT/CVTs that seem to confuse a lot of drivers. Just visit forums from other brands!

Thanks for elaborating Jolly and I'm impressed by your knowledge and details you were able to provide, really interesting (assuming they're correct .
Always refreshing to read your posts, keep it up!