CVT and cruise control

[keith3267]

I just got back from my summer road trip in my 14
Subaru Legacy. Normally I do not use cruise control unless my foot or
leg gets really tired or painful. I noticed something unusual. I'd be
cruising along at a set speed on flat ground, say 2400 rpm at 80 mph and
if I turn on the cruise control, within a minute or so, the tach would
jump up to 32-3400 rpm. If I shut off the cruise control and held the
same speed, I'd be back down to 2400 rpm. The only way to control this
was to put the transmission in manual and use the paddle shifter to make
sure I was in the 6th gear range.

Has anyone else noticed this behavior with a CVT in cruise control? I
also found that when I would hit the resume button after dropping a
little speed from using the brakes, the throttle would go WOT and the
tach would go almost to redline until the car got back up to speed.
Never had a cruise control do that before.

 

[matt167]

Subaru CVT is like driving a rubber band powered car. Tried and hate them for that reason

[gbhrps]

keith3267,

 

My 2012 OBW has the same CVT .... and I LIKE it!

 

First off, I've never owned a car in 51 years of driving where I have ever put the cruise control on at 80 mph, so I can't answer your first question.

 

As for the WOT accelerating back up to your previously set speed, I have to agree that I've seen the same thing. So I don't allow the cruise control to get the car back up to the set speed on its own. I accelerate the car back up to the set previous set speed my self, or close to it, before I press the resume speed control. Its much less dramatic, and a practice I learned years ago. It also saves fuel.

 

If I had any complaint about the CVT, it would be to get rid of that rediculous ECNO gauge that Subaru introduced at the same time and bring back a usable Temperature gauge.

[keith3267]

Its not the CVT I have a issue with, its the cruise control.  And come to think of it, I was doing a check of the speedometer on a long flat and mostly empty stretch of highway somewhere in the southwest (Texas ?) a couple of years ago where I set the CC on 80 for one hour ad used the mile markers for distance.  One hour later, 79.7 miles.  I don't remember the transmission shifting to a lower ratio then, but I might have been in manual mode as I often do on trips.

 

It acts like the cruise control changes the shift profile of the trasmission when it is engaged, the transmission is just doing what it is told to do.

 

I also manually resume speed because of how the CC acts, but I just don't use CC very often.  I drive my cars and if I weren't sharing the car with my wife, it would have a manual transmission.

Edited August 28, 2016 by keith3267

[wtdash]

Hi,

If this is indeed 'new behavior' and the car is under warranty, have it checked out. Might be a CVT software update.

Sounds like what an Auto trans would do when the Torque Converter unlocks/locks.

 

TD

Edited August 29, 2016 by wtdash

[Numbchux]

The transmission control unit changes shift maps when the cruise control is engaged, this has been the case since Subaru started using the 4EAT (might have been true on the 3AT, even my '92 Celica cruise control was connected to the overdrive solenoid to kick it down).

 

I suspect there's a reason for this, as they've been doing it forever, but I don't like it. I cut that wire on our '04 Outback VDC so it doesn't dump the thing into 3rd going almost 80mph just because there's a slight incline.

[LosDiosDeVerde86]

keith3267,

 

My 2012 OBW has the same CVT .... and I LIKE it!

 

If I had any complaint about the CVT, it would be to get rid of that rediculous ECNO gauge that Subaru introduced at the same time and bring back a usable Temperature gauge.

 

I like my 2010 CVT as well. Also, my '16 Outback does have an actual temp gauge and the eco meter is now part of the screen.