I just replaced my tps because it wouldnt even let my truck in O/D. So i did and it wroked great let it in overdrive and everything . But the day it started going out i noticed for the first time the tranny temp light would come on when it would shift out of O/D or just unlock the Torque converter. I figured the sensor would fix that problem well it didnt so every time my tranny temp light comes on my truck will down shift hard and rpm's will fly annyone had this problem? If so pls help i cant drive anywhere when it keeps shifting down!

 

If the tranny gets hot the pcm won't let OD engage.
It would be good to find out what temp your tranny is actually running at. Instead of getting complicated it might be easier to just replace the trans temp sensor and see if that changes it.

 

what is the temp where it will malfuction or meltdown temp i could say?

 

Anything over 180F will start degrading your ATF, over 240° where the computer tells the tranny to kick out of OD and the idiot light comes on will start ruining your fluid in a matter of minutes.

I've seen a chart that tells how soon to replace your ATF after reaching certain temperatures but can't find it.
As I recall it said to replace your fluid as soon as possible after reaching 240°.
Heck of a lot of good the idiot light does if that's the case.

 

i hadsame problem the transtemp sender plug wasent making good contact i shoved 3 strands of small copper wire into the 2 female tabs on the plug has worked flawless for 4 months now. when it was doing it to me it would randomly down shift and the light would come on i looked at my trans temp guage it was under 100* F its just loose free fix dont replace it.

 

before i knew this i replaced the TPS and cleaned every ground ON THE TRUCK , bought a torque converter and valve body got amsoil deep dish tranny pan and a bd tranny cooler , trying to fix it and wound up fixing the stupid thing for free man if i only knew try this before you buy any thing.!!!!