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) (EXCEPT FOR STI)>Clear Memory Mode>OPERATION , and inspection mode Ref. to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>Inspection Mode>PROCEDURE .

Use the check board when measuring the ECM terminal voltage and resistance.

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM>Engine Electrical System>WIRING DIAGRAM .

G09480903

Courtesy of SUBARU OF AMERICA, INC.

CHECK DTC .
Read the engine DTC using the Subaru Select Monitor or general scan tool. Ref. to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>Read Diagnostic Trouble Code (DTC) .

Is DTC other than P0116 displayed? (Current malfunction)

Yes: Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)". Ref. to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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) (EXCEPT FOR STI)>Engine Coolant Temperature Sensor .