2004 explorer auto trans keeps downshifting back and fourth from high to 3rd

when this started happening i noticed that the cold idle would go to 1500
rpm, then take it's time to come down to normal, then when warm it still
goes to 1500 rpm then comes down to normal rpm a little quicker, at the
same time the transmission shifts normal, but between 45 and 55 mph the
trans downshifts from high down to 3rd, then back and fourth from high to
3rd, any suggestions

Not sure if this applies to the '04's, but a similar problem on my '96 was
recently fixed by replacing
the engine coolant temp sensor (the one that feeds the engine computer, not
the one that feeds the dash gauge).
I figure it was telling the engine computer the engine wasn't at full
operating temperature, and in my case
it affected both warm and cold idle speeds, torque converter lockup, and
tranny shift points. YMMV

Steve.

"marlow" > wrote in message
lkaboutautos.com...
> when this started happening i noticed that the cold idle would go to 1500
> rpm, then take it's time to come down to normal, then when warm it still
> goes to 1500 rpm then comes down to normal rpm a little quicker, at the
> same time the transmission shifts normal, but between 45 and 55 mph the
> trans downshifts from high down to 3rd, then back and fourth from high to
> 3rd, any suggestions
>

thanks for the info, i will check it out, marlow.