Engine Coolant Temperature Sensor
🛠 Fits: 1988-1998 C/K 1500 & 2500 (gasoline engines)
ECT sensor that feeds the computer (separate from the dash gauge sender)
213-928ACDelco (OEM)
📝 Two temp sensors on these trucks: this one talks to the PCM, a separate sender runs the gauge. Rough cold starts and rich running point here.