Scan Tool Data Definitions
WARNING: This page is about a different car, the 2007 Cadillac XLR. However, it is still accessible from the selected car via links, so may be relevant.
- Cooling Fan Motor Command
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The percent of PWM duty cycle requested from the ECM.
- Cooling Fan Command
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The percent of engine cooling fan commanded.
- ECT
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The scan tool displays -40 to +151°C (-40 to +304°F). The engine coolant temperature (ECT) sensor is mounted in the coolant stream. The powertrain control module (PCM) applies 5 volts to the ECT sensor circuit. The sensor is a thermistor which changes internal resistance as temperature changes. When the sensor is cold, internal resistance high, the PCM monitors a high signal voltage and interprets it as a cold engine. As the sensor warms, internal resistance decreases, the voltage signal decreases and the PCM interprets the lower voltage as a warm engine.