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DTC P0118 - ECT SENSOR CIRCUIT HIGH VOLTAGE Chevrolet Tahoe I

Note. For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Engine Coolant Temperature (ECT) sensor is a thermistor located in intake manifold cooling system passage used to monitor engine coolant temperature. VCM applies and monitors 5 volts to sensor. When engine coolant is cool, sensor resistance will be high and VCM will sense a high voltage signal. When engine coolant is warm, sensor resistance will be low and VCM will sense a low voltage signal.