Auto won't kick down up hill

[stricky]

When going up hills the Auto (2001 GU) does not kick back to 3rd even if the accelerator is fully depressed. Taking my foot off the accelerator and then putting it down again, the auto will select 3rd hitting about 2500 RPM but always then changes to 4th about 2-3 seconds later. I have tried playing with O/D both on and off and also the A/T Hold Power Switch without success. Not sure what I need to check, Auto or ECU or something else?

[pollenface]

Not sure if it's fluid related but how long since the tranny was serviced?

Perhaps a blockage in the valve body?

[Figjam]

These transmissions are not very smart and tend to avoid downshifting until most power is lost.
I have always found it easiest to drive in manual mode when this becomes an issue

[stricky]

How do you Drive manual in 3rd?

[Avo]

How do you Drive manual in 3rd?Put it in the 3,just below the D

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[pollenface]

or hit the O/D button if it has one

[stricky]

The auto only has 1st & 2nd manual gear options. I was doing some more investigation, is it possible the Throttle Position Sensor is the problem? I am not sure as the problem mostly occurs up hills.

[pollenface]

Do you have an O/D button on the stick under ya thumb (under the other big button)?

[stricky]

Yes, I have an O/D button. But I do not understand what it has to do with my problem.

[Avo]

Take the overdrive off..stick in 2nd or 1st...drive it like ya stole it...

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[pollenface]

Yes, I have an O/D button. But I do not understand what it has to do with my problem.

We're just saying if you want to lock it in 3rd up a hill turn the O/D off.