P0115moderate severityPowertrain
Engine Coolant Temperature (ECT) Sensor 1 Circuit
on 2004 Subaru Legacy 3.0L H6 · AWD
What this code means
General malfunction in the engine coolant temperature sensor circuit.
Symptoms
- Check Engine Light
- Poor fuel economy
- Hard starting
- Incorrect temp gauge reading
- Fans not operating correctly
Common causes
- Faulty ECT sensor
- Wiring damage
- Corroded connector
- Low coolant level
Diagnostic steps
- Test ECT resistance at known temperature
- Inspect wiring
- Check coolant level
- Compare ECT to IAT at cold start
Repair notes
Replace ECT sensor or repair wiring. Verify coolant level.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1