1999 Sienna Coolant Temp Sensor

[edoubleu20]

I'm trying to work through some codes to get through CT emissions and am down to a P0125 code. I replaced a bad thermostat and still have the code. I've done some research online and the ECT sensor comes up as a possible culprit. How many are there in this vehicle? I found one on the passenger side near the radiator fill cap. I also see a sensor on the driver side on the thermostat housing. This sensor only has 1 wire though.
Can anyone tell me what this is?

Thanks

[wiswind]

The device on the thermostat housing with the wire is Coolant Temperature Switch #2.
This is used for Radiator fan control.
Switch #2 is Closed (low resistance between terminals) above 201 degrees F
Switch #2 is OPEN (no continuity) below 181 degrees F


There is another Coolant Temperature Switch (#1) on the front of the motor.
Switch #1 is CLOSED below 190 degrees F
Switch #1 is OPEN above 208 degrees F

These are a open/closed switchs that activate at specific temperatures.

There are 2 coolant temperature sensors over next to the coolant cap.
These are thermistors, resistors that vary in value as temperature changes.
1 is for the computer and the other is for the gauge.
In other words, the Gauge has its own sensor and the computer has its own sensor.
It is hard to get a good picture of both of these sensors at the same time.
The diagrams show them to be very close together, with the sensor for the Gauge to be slightly more forward than the sensor for the computer.....but they are within inches of each other.

Here is a picture that shows 1 of the sensors on my 2003, with the upper intake manifold removed.
The other sensor is covered by the wires.

[engine1CD]

there are 3 sensors.
1.water temperature sender 89428-41010 located . left end
2. switch temperature detect 89428-30130 located right end vertical
3. switch temperature detect no2. 89428-45010 located right end horizontal