P0115 — Engine Coolant Temperature Sensor Circuit Malfunction
Category: Powertrain Severity: Medium
Updated:
DTC code P0115 means: Engine Coolant Temperature Sensor Circuit Malfunction. It falls under the "Powertrain" category, with an estimated severity of Medium. Common causes include failed coolant temperature sensor, loose or corroded connector and damaged wiring; it's worth confirming the diagnosis before replacing parts.
Possible causes
- Failed coolant temperature sensor
- Loose or corroded connector
- Damaged wiring
- Low coolant (sensor exposed to air)
Symptoms
- Cooling fan runs constantly
- Hard cold starts
- Higher fuel consumption
- Incorrect temperature gauge
How to diagnose it step by step
- Check the coolant level.
- Read coolant temperature on a cold engine.
- Inspect connector and wiring.
- Measure sensor resistance.
- Replace the sensor.
How to fix it
Check the coolant level first. Then compare the sensor reading on a cold engine (it should match ambient). If not, replace the sensor.
Estimated repair cost
Sensor: $15–70; $50–150 installed.
Frequently asked questions
What does DTC code P0115 mean?
Engine Coolant Temperature Sensor Circuit Malfunction.
Is code P0115 serious?
Severity Medium. Not urgent, but worth diagnosing to avoid bigger damage.
Can I keep driving with code P0115?
You can drive while watching the temperature; don't if the gauge doesn't work and you can't tell if the engine overheats.
Related codes
P0116 P0113 P0117 P0112 P0118 P0110 P0120 P0121 P0108 P0122
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