Dtc P0116 Engine Coolant Temperature Circuit Range / Performance Problem


DESCRIPTION

MONITOR DESCRIPTION

INSPECTION PROCEDURE

CHECK OTHER DTC OUTPUT (BESIDES DTC P0116)

INSPECT WATER INLET WITH THERMOSTAT SUB-ASSEMBLY (THERMOSTAT)

DTC P0116 Engine Coolant Temperature Circuit Range / Performance Problem


DESCRIPTION

Refer to DTC P0115 (Toyota Fortuner RM000000UCS00JX.html).

DTC No.
DTC Detection Condition
Trouble Area
P0116
Engine Coolant Temperature (ECT) between 35°C and 60°C (95°F and 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
  1. Cooling system
  2. ECT sensor
  3. Thermostat (water inlet)

MONITOR DESCRIPTION

The ECT sensor is used to monitor the ECT. The ECT sensor has a thermistor that varies its resistance depending on the temperature of the engine coolant. When the ECT is low, the resistance in the thermistor increases. When the temperature is high, the resistance decreases. The variations in resistance are reflected in the output voltage from the sensor.
The ECM monitors the sensor voltage and uses this value to calculate the ECT. When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the ECT sensor and sets the DTC.
Examples:
Upon starting the engine, the ECT is between 35°C and 60°C (95°F and 140°F). If after driving for 250 seconds, the ECT still remains within 3°C (5.4°F) of the starting temperature, a DTC is set (2 trip detection logic).

INSPECTION PROCEDURE

HINT:
  1. If DTC P0115, P0116, P0117 and P0118 are output simultaneously, the ECT sensor circuit may be open or shorted. Perform the troubleshooting on DTC P0115, P0117 or P0118 first.
  2. Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.
1.CHECK OTHER DTC OUTPUT (BESIDES DTC P0116)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON and turn the tester ON.

  1. Enter the following menus: Powertrain / Engine and ECT / DTC.

  1. Read DTCs.

    Result:
    Display (DTC output)
    		Proceed to
    Only P0116 is output
    		A
    P0116 and other DTCs are output
    		B
    HINT:
    If any other codes besides P0116 are output, perform troubleshooting for those DTCs first.


B
GO TO RELEVANT DTC CHART
A


2.INSPECT WATER INLET WITH THERMOSTAT SUB-ASSEMBLY (THERMOSTAT)

  1. Inspect the water inlet with thermostat sub-assembly (Toyota Fortuner RM000001462003X.html).



NG
REPLACE THERMOSTAT
OK

REPLACE ENGINE COOLANT TEMPERATURE SENSOR