2007 Hyuandi Tuscan V6 P0711

Happy holidays everyone.
Long time reader (over a decade) but a rare poster here.
So I “inherited” this car with only 50,000 on the clock from my father-in-law, who can’t drive any longer.
Car runs and shifts great. Body is good shape.
It’s one problem, it randomly throws a P0711 code.
Had the temperature sensor in the tranny changed , thought problem was solved ($400 by the way). My mechanic bought, but didn’t change the harness. He said that there are over six hours of labor involved with changing this harness. Anyways, was fine for about a month, then it went off again. Sometimes it can go 300-400 miles, no CEL, then it goes off. I pull out my scan tool, clear the codes, it may go off in 5 miles or 500 miles later before of trips again. No change in performance either way.
Any ideas besides the obvious, change the harness?
Should I just keep clearing the codes until it’s inspection time (getting everything to “set” before the code goes off again should not be a problem).
Am I permanently damaging the tranny?
I know, little exact advice can be given by you guys without actually inspecting the vehicle.

Has anyone connected a scanner to the vehicle that can monitor the actual transmission fluid temperature?

Maybe the transmission is overheating under certain conditions.


No. I was wondering the same thing because it seems to be happening more often this month (as it gets warmer).
It’s now being used as a second car because we have a new one, so it’s mostly being used for local traveling.
One question though, if the tranny was indeed overheating, wouldn’t it show in performance (slipping, etc)?

If you run the transmission long enough while it’s overheating, eventually it’ll start slipping.



The list of things that can cause that code are 1, a bad sensor or 2 and.open or short or 3 a bad connection. You did 1

The problem acts exacrly like a short or open wire but you can confirm it by taking real time data and watching for data drop outs in the trans temp signal.

Thank you both.
Now I have something to bring to my mechanic.

My guess, the transmission fluid is actually overheating. Any unusual driving conditions, uphills, towing? Any problems with the engine cooling system, overheating, having to add coolant? Engine compartment fans all working correctly, at the right speed? Any radiator problems? Transmission fluid at correct level and in good condition? If all that’s ok, consider to have a routine transmission service done, replacing the fluid and the filter (as applicable for your configuration). A dose of fresh fluid may be all it needs. Replacing the radiator is another possibility. Remember the radiator (on most cars) is also what cools the transmission.