Dtc P0116 Engine Coolant Temperature Circuit Range / Performance Problem

DESCRIPTION

MONITOR DESCRIPTION

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

CONFIRMATION DRIVING PATTERN

INSPECTION PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0116)

INSPECT THERMOSTAT

DESCRIPTION

MONITOR DESCRIPTION

1. Engine coolant temperature sensor cold start monitor
   When a cold engine start is performed and then the engine is warmed up, if the engine coolant temperature sensor value does not change, it is determined that a malfunction has occurred. If this is detected in 2 consecutive driving cycles, the MIL is illuminated and the DTC is stored.
   

1. Engine coolant temperature sensor soak monitor
   If the engine coolant temperature sensor value does not change after the warmed up engine is stopped and then the next cold engine start is performed, it is determined that a malfunction has occurred. If this is detected in 2 consecutive driving cycles, the MIL is illuminated and the DTC is stored.
   

1. ECT sensor high side stuck monitor (only for Mexico models)
   The ECM monitors the sensor voltage and uses this value to calculate the ECT. If the sensor voltage output deviates from the normal operating range, the ECM interprets this deviation as a malfunction in the ECT sensor and stores the DTC.
   Examples:
   
   1. Upon starting the engine, the ECT is between 35 and 60°C (95 and 140°F). If after driving for 250 seconds, the ECT remains within 3°C (5.4°F) of the starting temperature, the DTC is stored (2 trip detection logic).
      
   2. Upon starting the engine, the ECT is over 60°C (140°F). If after driving at varying speeds (accelerating and decelerating) for a specified period of time, the ECT remains within 1°C (1.8°F) of the starting temperature, the DTC is stored (6 trip detection logic).
      

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.
   
2. Turn the ignition switch to ON and turn the Techstream on.
   
3. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
   
4. Check that the engine coolant temperature is 60°C (140°F) or less.
   
5. Clear DTCs (even if no DTCs are stored, perform the clear DTC procedure).
   
6. Turn the ignition switch off and wait for at least 30 seconds.
   
7. Turn the ignition switch to ON and turn the Techstream on [A].
   
8. Start the engine and idle it for 5 minutes or more [B].
   

   HINT:

   If the engine coolant temperature does not change by 5°C (9°F) or higher, the engine coolant temperature sensor is malfunctioning. It is not necessary to continue this procedure.

9. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].
   
10. Read pending DTCs.
    

    HINT:

    1. If a pending DTC is output, the system is malfunctioning.
       
    2. If a pending DTC is not output, perform the following procedure.
       
11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    
12. Input the DTC: P0116.
    
13. Check the DTC judgment result.
    
    

    Techstream Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
    N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    1. If the judgment result shows NORMAL, the system is normal.
       
    2. If the judgment result shows ABNORMAL, the system has a malfunction.
       
    3. If the judgment result shows INCOMPLETE or N/A, perform steps [D] and [E].
       
14. Drive the vehicle at 40 km/h (25 mph) or more for a total of 5 minutes or more [D].
    

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

    HINT:

    In the event of the drive pattern being interrupted (possibly due to factors such as traffic conditions), the drive pattern can be resumed.

15. Check the DTC judgment result again [E].
    

    HINT:

    If the judgment result shows INCOMPLETE or N/A, perform steps [D] and [E] again.

16. If no pending DTC is output, perform a universal trip and check for permanent DTCs (YARIS_NCP93 RM000000PDK0T5X.html).
    

    HINT:

    1. If a permanent DTC is output, the system is malfunctioning.
       
    2. If no permanent DTC is output, the system is normal.
       

INSPECTION PROCEDURE

HINT:

1. If any of DTCs P0115, P0117, P0118 or P0125 are output simultaneously with DTC P0116, the engine coolant temperature sensor may have an open or a short circuit. Troubleshoot those DTCs first.
   
2. Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
   
3. When the DTC is output, check the engine coolant temperature using the Techstream. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp. If the Coolant Temp value is lower than the actual engine coolant temperature, the engine coolant temperature sensor circuit may be malfunctioning. In this case, check the wire harnesses and connectors (and those connections) between the ECM and the engine coolant temperature sensor first.
   

1. Connect the Techstream to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the Techstream on.
   

4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
   

5. Read DTCs.
   

   Result

   Result	Proceed to
   DTC P0116 is output	A
   DTC P0116 and other DTCs are output	B

   HINT:

   If any DTCs and other than P0116 are output, troubleshoot those DTCs first.

1. Inspect the thermostat (thermostat opening temperature) (YARIS_NCP93 RM000001DG801EX.html).
   

   HINT:

   Perform "Inspection After Repair" after replacing the engine coolant temperature sensor (YARIS_NCP93 RM000004NJD006X.html).