Scan Tool Data Definitions
WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
- ECT
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The scan tool displays -40°C to +151°C (-40°F to +304°F). The engine coolant temperature (ECT) sensor is mounted in the coolant stream. The engine control module (ECM) applies 5 volts to the ECT sensor signal circuit. The sensor is a thermistor which changes internal resistance as temperature changes. When the sensor is cold and the internal resistance is high, the ECM monitors a high signal voltage and interprets it as a cold engine. As the sensor warms and the internal resistance decreases, the voltage signal decreases and the ECM interprets the lower voltage as a warm engine.
- Fan Control 1, Fan Control 2 Command
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The cooling fan relay is commanded ON or OFF by the ECM.
- Low Coolant Level, Switch Inputs
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The scan tool displays YES or NO, determined by the state of the low coolant level switch.