Monaco V6-182 3.0L SOHC (1990)
Coolant Temperature Sensor/Switch (For Computer): Description and Operation
Coolant Temperature Sensor
The coolant temperature sensor is installed in the thermostat housing where it maintains constant contact with the engine coolant. The ECU sends out a
reference voltage of approximately five (5) volts to the coolant temperature sensor. As coolant temperature changes, the internal resistance of the sensor
will change, causing a voltage drop across the sensor. The ECU reads the voltage drop across the sensor, and therefore the engine temperature.
Based on the amount of voltage drop at the coolant sensor, the ECU will:
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Adjust the fuel injector pulse width. A cold engine will receive a longer pulse width, allowing for a richer mixture.
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Compensate for condensation of fuel in the intake manifold.
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Monitor and adjust engine warm-up speed.
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Advance ignition timing when the engine is cold.
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Activate the EGR valve solenoid to prevent vacuum from reaching the EGR valve.
