P1115moderate severityPowertrain
Engine Coolant Temperature Sensor Circuit Malfunction
on 2015 Toyota Corolla 1.8L I4 · FWD
What this code means
The engine coolant temperature sensor circuit has failed or is out of range. The ECM cannot accurately read engine temperature for fuel and fan control.
Symptoms
- Check engine light on
- Hard cold starts
- Cooling fan running abnormally
Common causes
- Faulty ECT sensor
- Damaged wiring or connector
- Low coolant level
- Faulty ECM
Diagnostic steps
- Check coolant level
- Read ECT sensor live data
- Test sensor resistance vs temperature
- Replace ECT sensor if out of spec
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P0014
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P0015
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