Hi all,

I need some help! I'm a little bit stumped here.

My Sportage has an electrical radiator fan and the SPAL fan-pwm v3 controller. It is hooked up to the stock temperature sensor, the one used for the dashboard temp gauge, not the one the computer uses. I am thinking of changing that. Anyway...

The problem I'm having is it keeps throwing the P0128 code. This code means the engine took to long to warm up to operating temperature.

I thought my thermostat was the problem, but I have changed it a couple times now. One time it was upside-down and I thought that was the problem, but when I put it back the right way, the problem didn't go away.

I use the higher temperature thermostat. Autozone usually lists 2 thermostats for this vehicle, and I pick the hotter one. Still doesn't help.

Maybe my radiator fan is turning on too early. But I don't see how this would stop the engine from warming up. The thermostat should be closed when the engine isn't warmed up, so it shouldn't matter how cold the radiator water is, should it? Plus, what if I lived in a cold climate? The radiator water would be cold anyway.

Plus, I don't see how the fan could be the problem, because when I'm driving down the road, there will be more airflow through the radiator than the fan can supply! So if too much airflow on the radiator was the problem, the engine wouldn't be able to warm up just from driving down the road!

Anyway, so I'm puzzled. Any ideas? What else could it be?