P0115: Engine Coolant Temperature Sensor Circuit Malfunction
Severity: Moderate
What it means
The coolant temperature sensor signal is out of range or missing.
Common symptoms
- Hard starting
- Cooling fans running constantly
- Wrong temperature reading
Common causes
- Failed sensor
- Corroded connector
- Damaged wiring
What to check first
- Inspect the sensor connector for corrosion
Causes vary by vehicle. Confirm with testing before replacing parts.
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