Strange Transmission Issues - 2007 Yaris 4door hatch.

[Nibby99]

I bought my 2007 Yaris used (about 20,000km on it - was a rental car previously) and it is an automatic. I generally drive in (D) as most people and the manual suggest. But a few weeks after I got it it seems to be doing the strangest things... I will go to work in the morning and start driving up my street, the COLD indicator will normally be on for 2-3 minutes and during this period I swear to god it sticks in either 1st or 2nd. Literally if I push on the gas pedal to any degree I can easily get it up to 5000rpm and then finally (several hundred yards later) it usually shift up but I'm not entirely sure if it I really pushed it I suspect it'd hit 6-7k rpm. Usually after the cold indicator goes off it drops about 1000-1500rpm and shifts a bit better.

Also another oddity is there is a very gentle down sloping corner as I turn into my street. If I keep even pressure on the gas pedal and make the corner the engine seems to rev up to 2000rpm doesnt increase forward speed then seems to 'grab' or surge forward once I've made the corner. Regardless awhile back I brought it to a dealership they did the maintainence on it checked fluids etc.. took it for a drive and didn't notice a thing (although it had warmed up nearly an hour during the drive to the dealership).

Anyone have any input on this ? I'd attribute it to driving style but I can say I've driven it consistently since I got it and this seems to be new.

[bgrieger]

I had a rental a couple of weeks back that acted the same way. It was a rental though so I never cared that much if it did explode on the street. It may be a computer control, or just cold fluid creating too much line pressure.

[ECHOKnight2000]

I know or can guess for the transmission not shifting into 4th is "normal" at least when its cold for autos of course. Its suppose to do that, annoying yes but its for emissions reasons, so the engine can warm up faster so the tranny doesn't shift into the overdrive gears (4th) until it warms up. It does this for my ECHO and it did this for my 87 Toyota Van when I had it.

The second part, not too sure but good luck!