2009 Corolla/Matrix XRS 5 Speed Auto Trans problem

I have 2009 Corolla XRS 5 speed automatic. I have 10,500 miles on it and I have had this transmission issue since I got the car. At times, while accelerating onto highways the car does not downshift. The car stays in 3rd gear up until 4,000 RPM. I can shift it by putting it in sport mode and shifting manuly. It only does it sometimes but it does not seem normal. Took it for my 1st service visit dealer said no codes came up on the computer and maybe it needed to be broken in. Went for 2nd service dealer told me no codes and no problems. I then wrote a letter to Toyota under the lemon law since it had 2 failed attempts at fixing it. They contacted me and it really does not fall under a lemon but the head tech guy for the northeast will look at it a week from thursday. He again said this may be normal. I do not see how it is normal. Does anyone else have the same problem with their 09 corolla/matrix XRS automatic transmission? Any help would be greatly appreciated.

Is it because it is a four cylinder that it has these problems? Usually it shifts correctly but I feel there is a defect but they said the computer would have codes stating problems and it does not.

On top of this it seems to shift somewhat roughly? My former car was a 6 cylinder and never had this issue, could the problems be because it is a four cylinder?

Wish I could say I know what you mean. I own a '03 Pontiac Vibe with an older 4-speed auto tranny and I believe that it is definitely programmed to shift for economy. There is a noticeable delay between gear changes which is very annoying during acceleration. What momentum I had going is sucked away as the tranny upshifts.

I'll suggest 2 things:
1) Check the tranny fluid and see if it is overfilled. Toy trannies are fussy about how full they are. Overfill them and they get very quirky. Also check the fluid's color and odor. It should still be bright red and clear. If it is a pale red or borderline colorless, it's time for a change. I don't know if the owner's manual specifies a break-in fluid change...typically not...but under severe driving conditions it may not hurt.

2) Ask the dealership to test drive another car with the same engine/transmission. Do similar tests on it and see if it behaves the same way. Also check the trans fluid to see its color, level, etc., as a good baseline for where you should keep yours. Did you test drive a car before you bought this one? How did it behave?

I would expect the sport version to be programmed for crisper shifts and better response but who knows. Keep us informed and good luck!