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Ensures the engine does not overheat by measuring the temperature of the engine coolant
Troubleshooting:
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Symptoms:
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Engine backfires or cuts out
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Black smoke appears from the exhaust pipe
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Fuel economy has rapidly decreased
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Possible causes for failure:
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Circuit broken between sensor and ECU
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Damaged wire connector
Testing
To test the coolant temperature sensor disconnect it from its electrical connectors. Ensure that the ignition is turned off before disconnecting.
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If the switch is located at the top of the radiator check the coolant levels. If the level is low the switch will not be able to read the temperature of the coolant.
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Check surrounding wires for corrosion and damage and ensure that a current is being sent to the switch by connecting a voltmeter to the electrical connectors.
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Check the resistance of the part by connecting a multimeter to the sensor terminal and then insert the sensor back into the engine. For this the multimeter will need to be set to ohm x 1,000. When the ignition is turned on, the multimeter reading should be between 2,200 and 2,700 ohm. As the sensor temperature increases the resistance value will decrease.
Common Fault Codes
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P0115 Engine Coolant Temperature Circuit Malfunction
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P0116 Engine Coolant Temperature Circuit Range/Performance Problem
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P0117 Engine Coolant Temperature Circuit Low Input
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P0118 Engine Coolant Temperature Circuit High Input
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P0119 Engine Coolant Temperature Circuit Intermittent
