Hi Dear!
I have gone through the complete thread and found it to be exactly same problem i have started feeling in my Passo 2015 KGC30 CVT having an FE Oil as per OM book. The problem firstly reported by my wife 4 weeks ago who is primarily driving the car since (purchased imported) last 1.5 years. So it not a Placebo or a Psycho type of thing which others have started bashing rather than coming to a solution / proper advise GURUS!!!!
Upon feedback i cross checked it and started noticing that a Shudder / jolts comes when the car is rolled in the morning after cold starting warm up (1/2 mins) touch driving pulling between 20-40km/hr speed. This shudder reduces to humming after car being warmed up / driven few kms when the JW cold indication goes off but despite how much warmed up the car is that humming / shudder is felt in the steering wheel.
For your info car is at 31000kms. I have replaced the oil (CVT FE) thinking that may be it is over looked (time wise) which makes it a bit smoother but the humming is there. (Two times replenishment done by collecting approx 2.5 liter each time from drain plug without opening sump. CVT FE fresh Oil consumed 5 liters approx. You can say it sweetening to max as the mileage is low and the oil color found almost like new. )
it feels like a manual trany being put from 2nd to 4/5th gear at speed between 20 to 40 or a slight slip age when a high mileage manual car 1st gear is engaged and clutch is released . A casual quick acceleration crossing this particular range is smooth but trying to accelerate touch paddle light pulling in that zone makes it hum and shudders little but felt considerable.
Tried to consult with Guru Friends, I am not sure but what i am feeling is (I could be wrong too as this is not my patent field) Torque converter is deteriorating prematurely.
Passo CVTi 1.0 KGC30 2015 and Garande 1.8 CVTi 2015to date share same CVT type. I feel it to be a manufacturing flaw which popped up at 30 / 60k kms.
What i am doing now from my own under standing, same instructions given to wife. In winters now a days after 1/2 mins warm up. Used to start moving initially in S mode which makes the rev higher enough to warm up the CVT faster (It do not do any abnormal hum in S all smooth like silk). Shift it to D when the JW temp cold indication goes OFF lets say after 1 / 2km.
Lets see how long it lasts as the things got a bit better by adopting this.
GURUS..... Toyota CVT reliability is a big Question now a days!!!!
Funny thing is its fuel economy is also increased 2km/l on avg. hahahahahaha may be Placebo effect..... So no need to finger spark plugs , TB, fuel filter, injectors or anything else. Above 40 it is smooth altogether till 150/160 top speed or what ever speed one drive constantly.