P0116

DTC P0116 - ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT LOW INPUT

DTC DETECTING CONDITION:
- Immediately at fault recognition

TROUBLE SYMPTOM:
- Hard to start
- Erroneous idling
- Poor driving performance

CAUTION: After repair or replacement of faulty parts, conduct CLEAR MEMORY MODE and INSPECTION MODE. Refer to How To Clear Diagnostic Trouble Codes. Clearing Diagnostic Trouble Codes





WIRING DIAGRAM

10H1: CONNECT SUBARU SELECT MONITOR OR THE OBD-II GENERAL SCAN TOOL, AND READ DATA.
1) Turn ignition switch to OFF.

2) Connect Subaru Select Monitor or the OBD-II general scan tool to data link connector.





3) Turn ignition switch to ON and Subaru Select Monitor or OBD-II general scan tool switch to ON.

4) Start engine.

5) Read data of engine coolant temperature sensor signal using Subaru Select Monitor or OBD-II general scan tool.

NOTE:
- Subaru Select Monitor
For detailed operation procedure, Refer to the "READ CURRENT DATA SHOWN ON DISPLAY FOR ENGINE". Refer to Normal Scan Data Values.
- OBD-II general scan tool
For detailed operation procedures, Refer to the OBD-II General Scan Tool Instruction Manual.

CHECK: Is the value greater than 150°C (302°F)?

YES: Go to step 10H2.

NO: Repair poor contact.

NOTE: In this case, repair the following:
- Poor contact in engine coolant temperature sensor.
- Poor contact in ECM.
- Poor contact in coupling connector (B122).

10H2: CHECK HARNESS BETWEEN ENGINE COOLANT TEMPERATURE SENSOR AND ECM CONNECTOR.
1) Turn ignition switch to OFF.

2) Remove air intake duct and air intake chamber assembly as a unit.





3) Remove engine harness connector bracket from cylinder block.





4) Remove blow-by hoses.





5) Disconnect connector from engine coolant temperature sensor.

6) Turn ignition switch and Subaru Select Monitor or OBD-II general scan tool switch to ON.

7) Read data of engine coolant temperature sensor signal using Subaru Select Monitor or OBD-II general scan tool.

NOTE:
- Subaru Select Monitor
For detailed operation procedure, Refer to the "READ CURRENT DATA SHOWN ON DISPLAY FOR ENGINE". Refer to Normal Scan Data Values.
- OBD-II general scan tool
For detailed operation procedures, Refer to the OBD-II General Scan Tool Instruction Manual.

CHECK: Is the value less than -40°C (-40°F)?

YES: Replace engine coolant temperature sensor.

NO: Repair ground short circuit in harness between engine coolant temperature sensor and ECM connector.