P0116 Error code

Just logging my personal maintenance here for myself.

Was thrown a P0116 error code with the only symptom being slightly rougher idling.

Pulled out the ECT sensor, and confirmed with the multimeter that there was a resistance of 3 ohms. This means the ect sensor is in good condition.

Wiring harness looked in good condition.

Next, pulled out the thermostat and noticed it seemed to be stuck in the open position. Replaced, cleared the error code and noticing better mileage and idling.

Will update if the error code comes back. Hope that helps somebody.

 

Toyota thermostat that failed or aftermarket?

 

I believe it was aftermarket, but not sure. Another thing I noticed is my heater works better now as well.