2012 Auto Yaris shifting issue

[thommo]

Our daughter has a 2012 Yaris YRS Auto 1.5L with about 130,000kms on it.

Recently she says after a hard acceleration on the highway where it drops back to 3rd (e.g. when overtaking), it will sometimes not then shift back to 4th (overdrive?) unless she manually shifts it to 3rd, then back to Drive.

Anyone know the likely problem & a fix?

Will an ATF & filter change make a difference?  Or is it going to be big bucks?

cheers

Edited December 14, 2018 by thommo

[campbeam]

9 hours ago, thommo said:

likely problem & a fix

Not an automatic transmission specialist but knowledgable enough to guess that the shifting issue is most likely related to the valve body rather than a shifting solenoid.

9 hours ago, thommo said:

Will an ATF & filter change make a difference?

In my opinion, YES. New ATF will help to clean the channels in the valve body and smoother gear changes. The Yaris has a capacity of only 2.5 litres for the ATF so I would be inclined to check/change the fluid on a regular basis. I would expect after 130,000kms that there would be a fair amount of accumulated sludge on the transmission pan.

https://www.datateck.com.au/Lube/PenriteAus/

9 hours ago, thommo said:

going to be big bucks?

Usual outcome when warning signs are ignored. Regular servicing/maintenance is going to maximise the life of the automatic transmission. I change the ATF in the transmission pan every 12-18 months. Filter has been replaced and next scheduled in 40/50,000kms.

[thommo]

Yes, the service book says the ATF only needs to be inspected, not changed but I'll get the local Toyota dealer to do a change & see how that goes.

My wifes 2006 VW Jetta says the same thing - no need to change the ATF in it's lifetime, but it started doing some hash shifts, so we had the fluid & filter changed @ 110,000 kms and that fixed it.  In the US they are now recommending an ATF change at 80,000kms in that VW, but that prescription has not hit Australia.

[campbeam]

3 hours ago, thommo said:

service book says the ATF only needs to be inspected, not changed

Inspect the ATF then decide whether it needs to be changed.

https://www.pepboys.com/auto-care/maintenance/transmission-fluid-color

4 hours ago, thommo said:

no need to change the ATF in it's lifetime

Lifetime from the vehicle manufacturer's perspective is 10 years and/or 160,000 kms and this is based upon "normal driving conditions". After reading lots of internet posts about automatic transmissions failing because the ATF has not been changed, I made certain to immediately change both the filter and ATF on my Aurion which I bought a few years ago with approx. 165,000kms on the odometer.  

[thommo]

Interesting, turns out my sister-in-laws auto Yaris is doing exact same thing.  After kicking back to 3rd up a hill, it can take up to 1km to shift back to 4th/overdrive.  Will be interesting to see if an ATF change fixes it.  Biggest concern is getting the local Toyota dealer to do it (no choice, regular mechanic will be closed for Xmas).  They charge like a wounded bull & have a reputation for screwing things up!

[campbeam]

10 hours ago, thommo said:

have a reputation for screwing things up!

Suggest you wait for your regular mechanic or go to an automatic transmission shop.