Grand Prix V6-191 3.1L (1989)
Coolant Temperature Sensor/Switch (For Computer): Description and Operation
Coolant Level Sensor
The coolant level sensor, is a solid state module that senses coolant level by means of two probes protruding into the engine coolant.
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When the coolant is at the proper level, the coolant level signal at the ECM is pulled low (0-3 volts).
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With low or no coolant, the signal at the ECM will be high (4-5 volts).
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When the signal voltage is high, the ECM will turn "ON" the low coolant level light.
