My 2003 Tribute has gotten into a mode where it frequently stalls when switching from Park or Neutral to Reverse. Idle speed is perfect at 750-800 rpm and, in fact the idle controller was replaced six months ago. I read that this might be caused by clogged transmission cooler line or fluid. Is that, in fact, the case? Fluid has never been changed. Might that be an issue? Fluid level looks fine, but fluid is sort of brownish rather than pinkish. No burned smell.

 

No codes? first thought was neutral safety switch/transmission range sensor. ~$70 from rockauto. but if it fails it aught to send some kind of code because it's a sensor. It's atop the transmission just below the thermostat and coolant hose intersection/coupling.. Not my favorite positioning there.. i'd be somewhat more confident if you did a thermostat recently. Are you sure there are no other faults?

Im going to be looking into the trans cooler shortly.. Had a trans cooler line shoot off. Could have been that the old spring clamp wasnt gripping the new hose well enough, but can't rule out obstruction yet.
Also, 03 3.0 FWD.

Also, is the idle jumping from 750 to 800 often?

 

Nope. No jumping, and no codes.

 

Mine did this, was a vacuum leak.