My wife’s 2008 Toyota Yaris has 201,560 km. Car runs pretty well all around, has had problems shifting out of third first thing in the morning pretty much since she got it used. I’ve driven it for a week now and as soon as the “cool” light symbol goes off it will shift to fourth, if I leave it warm up until the “cool” light goes off I have zero issue. Could this be a bad thermostat?

SOURCE: transmission problem shifting into high

My 97 Jimmy was doing the same thing, codes P0740 & P0753 witch are torqe converter lock up & shift solinoid. I unhooked the wires in the drivers side of the trany and cleaned them with contact cleaner bought at the parts store. I reconected the harness and disconected the baterie for a couple of houres and no trouble since.... 4 days so far Knock on wood........ Hope it helps

SOURCE: Adding daytime running lights to a 2008 Toyota Sienna

http://www.siennaclub.org/forum/index.php?showtopic=3772

DRL's can be added simply by adding a 20 amp fuse into an empty slot in the fuse box.

SOURCE: Speedometer not working service engine soon light on

I would guess there is a relation between the inop speedo and the service soon light being on. Push OFF and WARM on the climate control panel and hold down together for 5 sec to read codes.engine and transmission require speed input to set engine/trans parameters accordingly. The car car is safely performing in a back up mode until repairs are made

SOURCE: Tranny wont shift into third gear.

you have to pull down the oil pan of the tranny. then take out the strainer inside attached to the tranny. dirt is clogging it making the sometimes shift and other not.

SOURCE: Check engine light comes on, car sputters, loses power

you need to change you crank shaft positioning censor