06. Since our test car doesn’t have the heater, it was easy for us to install the ECT (engine coolant temp sensor). Just make sure when installing your sensor that you use Teflon tape on the threads, and that it’s on the hot side of water flow—headed towards the radiator. You need to have the hottest temperature reading for the sensor to read and accurately tell the ECU what is going on. The wiring harness comes with specific plugs that can’t be mixed up with other plugs.