I have an 01 Sonata 4 cylinder. Recently the engine light has come on. Checking with an OBDII tester showed an error of "engine coolant temp circuit malfunction". I cleared the error and drove the vehicle the following two days before it reappeared. Any ideas? Thanks in advance.
You'll be interested in the Freeze Frame data when the code stored. The OBD-II tester you used may be able to give this to you. A very high temperature suggests the vehicle was overheating for some reason. A very low temperature (-40 degrees is common) suggests a coolant temp sensor problem or an open circuit in the sensor wiring (almost always the sensor). If the temperature is not at operating temp but not ridiculously cold, then you may be looking at an issue with the thermostat stuck open.
Do you have the actual code? That may help narrow things a bit.
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