[TommyDzHA]

Hi
I have a 2007 Honda Accord and the fan turns on right away and the RPMs are always high while idling.
Which of the two ECT sensors is responsible for this - engine light is on. Thanks

 

[WiiMaster]

What is the CEL code? What makes you jump to ECT sensor right away? Get the CEL code and go from there.

 

[TommyDzHA]

I am getting a code P0128 I have already replaced the thermastat and one of the ECT sensors and my machanic replaced the one on the engine. The code did not stop and I am thinking that one of the sensors is bad out of the box. Not the fist time that has happened. I know there is a way to test them by measuring the current produced at certain temps but I cant find the youtube anymore where the person displayed the cart showing the differnent reading for different tempratures.

 

[ckev70]

See if you have an ODB that scans and reports the ECT values. This will give a better sense as to which one is not reporting properly.
Here's the value for ECT Sensor 1 based on the WorkShop Repair Manual

 

[DonutLimo]

Here's a table that should help

ECT 1 I believe is the sensor up high near the EGR and thermostat and is the one the computer uses for performance. The other one is down low near the bottom of the radiator and is more for fan control.