[Pnut00]

There was one I saw on here a few years back with someone asking the same question about the same gizmo, i had never seen or heard of one either. Personally i cant imagine those would be as good at cooling the trans oil as going to the radiator, from what i can see you are relying on the cast iron block to conduct the heat to the cooling system and then to the radiator instead of it just going direct.

Only thing i can think of is that depending on the temperature in the country of its origin perhaps the radiator made it run too cold or hot, so maybe this was a stop gap for that country?

 

[Pnut00]

Most searching shows it to be an input speed sensor error in the trans, that has nothing to do with fuel levels as far as i know unless the extra weight at the back of the car when the tank is fill makes the sensor make contact and not when the tank is empty. I would start with that sensor and go from there, its the most obvious answer.

 

[Pnut00]

A follow up.

So my mechanic checked the sensor and its wiring, measured its resistance etc. and found that it is not faulty.

He then followed the other trail that I suggested - fuel issue, and this did lead to solution. Previous owner did a bad fix of fuel pump relay which worked for a while but failed me now, so he re-wired the relay and now it works.
I don't understand the topic thoroughly, but from his explanation I believe that as the wiring failed, resistance in it was too big and the pump couldn't work at full efficiency, fuel-starving the engine.

Apparently the error code was generated in a similar way as in the post on clublexus I mentioned above - ECU had no indication of a fuel-related issue so it expected fuel in the engine, but didn't get it (or enough of it) and generated P0175.

Perhaps this will come useful to another unfortunate soul in the future.

Glad you found the solution, where ever it ended up. Nothing beats good troubleshooting with the subject in front of you