April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P0116: Engine Coolant Temperature Sensor 1 Circuit Range/Performance: Notes

DTC detecting condition:

Detected when two consecutive driving cycles with fault occur.

Trouble symptom:

Hard to start
Improper idling
Poor driving performance

CAUTION: After servicing or replacing faulty parts, perform Clear Memory Mode Ref. to ENGINE (DIAGNOSTICS) (H4DO)>CLEAR MEMORY MODE>OPERATION ., and inspection mode Ref. to ENGINE (DIAGNOSTICS) (H4DO)>INSPECTION MODE>PROCEDURE .

CHECK DTC .
Read the engine DTC using the Subaru Select Monitor or general scan tool. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

Is other than DTC P0116 displayed? (Current malfunction)

Yes: Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) -

No: Go to 2 .
CHECK ENGINE COOLANT TEMPERATURE SENSOR .
1. Disconnect the connectors from the engine coolant temperature sensor.
2. Measure the resistance between engine coolant temperature sensor terminals when the engine coolant is cold and after warmed up.
  Terminals
  
  No. 1 - No. 2:
Is the resistance of engine coolant temperature sensor different between when engine coolant is cold and after warmed up?

Yes: Repair the poor contact of ECM connector.

No: Replace the engine coolant temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR .