I have a 2005 xb automatic. I have noticed that quite often the transmission will stay in 3rd and not shift into overdrive even at rpms close to redline. I can left off the gas and slow down and the only thing that gets it to shift when it hangs is turning the OD off and back on really quick. anyone else have this problem with their automatics??? Also, it isn't fluid cause I check it often.

 

ive had the same problem, its time to chaange your tranny fluid

you should be doing it every 15K

once you do it it shifts like BUTTA

 

I find that hard to believe. I have 6000 miles on my 2005 xA and experience this daily and can reproduce this at will. I have to believe it is how the system is programed to shift.

I can make it happen if I go up a slight hill while applying the power...at the top of the rise, as long as the power is still applied it doesn't shift up. I'll look at the RPM's tomorrow and see where it is hovering while doing this.

If it is the tranny, I will return the car real quick and get my money back. 6000 miles is way too soon to even think of a tranny problem.

Andy

 

Look at your dash when this happens. Is there a blue light? Did you just start your car? The autos are programmed to not get into O/D while the engine is cold, which is what the blue light signals. It won't get into third when it's really cold. In winter you must let the car warm up a bit.

 

In the Scion literature the holding of the vehicle in gear, and not allowing upshifts until the speed/throttle position are more closely aligned with what the ECU expects is a DESIGNED IN FEATURE - it's SUPPOSED to work that way.

From one of their many descriptions:

Uphill Shift Logic (“Grade Logic”)
1. ECM can determine when climbing a hill by comparing the actual acceleration rate with the acceleration rate predicted based on throttle angle.
2. upshifts can be inhibited when lifting the throttle for a curve; this keeps the engine rpm in the peak torque band and provides a smoother ascent.

So long as the actual acceleration/speed is less than predicted by throttle position (hill climbing, high load, max throttle acceleration, etc.), the 'Grade Logic' program built into the vehicle's computer will inhibit upshifts.

Returning to a more normal operating environment allows it to reset.

(It also watches steering input to prevent shifts at bad times while cornering.)

(The comment about 'blue light' in the instrument cluster is right on, too - it will prevent shifts into overdrive until the engine is sufficiently warmed up for the 'puter to be happy.)

This is a computer controlled drivetrain - it has a WHOLE lot more tricks built in than the old Chevy V8's with Powerglide did... :D

 

You could contact your dealer and ask them instead of spending all day watching this thread for useful or useless information.
You're under warranty. It'll be fine

 

Another thing to do would be to look up info on the generic Toyota ECT - information a lot like ECT.pdf (580K), whick will explain a lot about how the ECT thinks and why...

The auto trans in the xA/xB is a fairly sophisticated unit with a lot of variables it look at to determinw what to do.

It also has a lot of very good features, including lockup on the top two gears for improved economy, etc.

My understanding is that, at least in the xB, the ECT and ECM learn together from their experience with the driver's driving style, and set themselves up to match that style - including even higher shift points for those who drive aggressively - to improve performance, and lower shift points for those who drive conservatively - to increase MPG.

(I think mine is probably confused cause I sort of alternate back and forth. Maybe I should reset everything and try 'conservative' mode to see what that does for mileage...)

 

Thanks for the VERY GOOD explanation of the computer controls programed and learned by our transmissions. My 1995 and 1998 Mercury Mystiques also had a sophisticated "learning mode".

When you say "Scion literature" what exactly are you refering to? I'll check the owners manual in the morning, but I suspect what you quoted is from a tech manual.

FYI. I understand the "blue light" delay in shift points. I experience this shift retarding when the xA is well warmed up and going up a grade on a curve at 45 mph. Actually feels kinda nice to have the engine "pulling" me up the grade.

Thanks,
Andy

 

well before i contacted the dealer i wanted to see if anyone else was having that problem. i don't think it is the tranny fluid since i only have 5400 miles on it. so when i go in for my oil change in a month i will have them put it on the computer

 

There is absolutly no reason to change your tranny fluid every 15K!

Stay with the factory specks- every 30-60k!

 

yeah every 15k is a little excessive unless you just gut the ____ out of your vehicle