SFI SYSTEM, Diagnostic DTC:P0116

DTC Code DTC Name
P0116 Engine Coolant Temperature Circuit Range / Performance Problem

DESCRIPTION

Refer to DTC P0115 Click here.

DTC No. DTC Detection Condition Trouble Area
P0116

Case 1:

Engine Coolant Temperature (ECT) between -40°C (-40°F) and 60°C (140°F) when engine started, and conditions (a) and (b) met (2 trip detection logic):

(a) Vehicle driven at varying speeds (accelerated and decelerated)

(b) ECT remains within 3°C (5.4°F) of initial ECT

  • Thermostat

  • ECT sensor

Case 2:

When either of following conditions met (2 trip detection logic):


  • During engine warming up after cold engine start, change in Engine Coolant Temperature (ECT) sensor output below threshold

  • In duration between warmed engine stopped and next cold engine start, change in ECT sensor output below threshold

MONITOR DESCRIPTION

Case 1:

The ECT sensor is used to monitor the ECT. The ECT sensor has a built-in thermistor with a resistance that varies according to the temperature of the engine coolant. When the ECT is low, the resistance of the thermistor increases. When the temperature is high, the resistance drops. These variations in the resistance are reflected in the output voltage from the ECT sensor.

The ECM monitors the sensor voltage and uses this value to calculate the ECT. If the sensor output voltage deviates from the normal operating range, the ECM interprets this deviation as a malfunction in the ECT sensor and sets the DTC.

Examples:

Upon starting the engine, the ECT is between -40°C (-40°F) and 60°C (140°F). If after driving for 250 seconds, the ECT remains within 3°C (5.4°F) of the starting temperature, the DTC is set (2 trip detection logic).

Case 2:

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 a DTC is stored.

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 a DTC is stored.

INSPECTION PROCEDURE

Tech Tips


  • If DTC P0115, P0117, P0118 or P0125 is set simultaneously with DTC P0116, the ECT sensor may have an open or a short circuit. Troubleshoot those DTCs first.

  • Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. 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.

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester ON.

    4. Enter the following menus: Powertrain / Engine / DTC.

    5. Read the DTC.

      Result
      Display (DTC Output) Proceed to
      P0116 A
      P0116 and other DTCs B

    B

    GO TO DTC CHART Click here

    A

  2. INSPECT WATER INLET WITH THERMOSTAT


    1. Remove the water inlet with thermostat Click here.

    2. Check the valve opening temperature of the thermostat.

      Standard
      80 to 84°C (176 to 183°F)

      Tech Tips

      In addition to the above check, confirm that the valve is completely closed when the temperature is below the standard.

    3. Reinstall the water inlet with thermostat Click here.


    NG

    REPLACE WATER INLET WITH THERMOSTAT Click here

    OK

    REPLACE ENGINE COOLANT TEMPERATURE Click here