What is the difference between the Engine Coolant Temp Sensor (ECTS) and the Coolant Temp Sensor. My Engine Coolant Temp Sensor is bad but i'm not sure which one to replace. Does anyone have a pic of what the ECTS and Coolant Temp Sensor look like? Thanks.

 

The coolant temp sensor is for the gauge inside your car.

The Engine Coolant Temp Sensor is monitored by the ECU for proper engine performance.

The 2 sensors are located near the thermostat housing on the engine block at the upper radiator hose. The sensor closest to the engine block is the Engine Temp Sensor. Thats the one you need to replace.

 

There's also a really good pic of where this sensor is located in the Hayne's manual (i believe page 3-7? or maybe 3-20?). it's easy to see if you remove some of your air intake tubing.