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

WARNING: This page is about a different variant/trim than selected.

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DTC detecting condition:

Detected when two consecutive driving cycles with fault occur.

Trouble symptom:
- Hard to start
- Improper idling
- Poor driving performance
Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM (IMPREZA MODEL)>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .
- IMPREZA MODEL
Courtesy of SUBARU OF AMERICA, INC.
- CROSSTREK MODEL
Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD .

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

CHECK DTC .
Using the Subaru Select Monitor or a general scan tool, read the DTC of [Engine]. Ref. to COMMON (DIAG)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC other than P0116 displayed? (Current malfunction)

Yes: Check the appropriate DTC using the "Diagnostic Trouble Code (DTC)". Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>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 (EXCEPT FOR HEV))>ENGINE COOLANT TEMPERATURE SENSOR .