The car was washed and then the engine light
came on the dashboard. Now it doesn't wanna
start and it's showing ECT?
That means that there is an error in the engine coolant sensor circuit, you could have a bad ECT sensor or there is a problem in the wiring for the sensor, a live data scanner would be able too tell you that in short order, but if you don't have one then you can either just replace the sensor and hope the wiring is good, or get your ohm meter out and measure the resistance to the temp and see if it matches the spec chart, if it does match, then you know you have a circuit problem and will have to trace it down. HTH