P2181-Cooling System Performance

[oboudreaux]

2007 KJ LTD getting a P2181 code.

ECT is reporting a constant 21C. Checked the resistance at ambient and it's 9.9k which seems right or wrong depending on where I look.

Anyone have a resistance chart for the ECT Sensor? If it's in spec I assume the thermostat is my next stop?

Thanks!

 

[ikuo78]

I don't know the specified value, but if you put it in 90℃ hot water and the resistance is the same, it's broken.
I think it will drop to about 0.5KΩ or less at 90℃.

I forget if the gauge and ECU use the same sensor.
Is the gauge also low?
I think it's unlikely since it's summer.
If you can touch the pressure tank or radiator after driving, the coolant temperature is really low.
Suspect the thermostat.

 

[oboudreaux]

Yeah, the gauge isn't budging. I pulled the sensor and it seems fine.
Replaced the t-stat. It's warming up now but it takes its sweet time.

Thanks for the help!