P0116

3MZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0116: Engine Coolant Temperature Circuit Range / Performance Problem

DTC P0116 - Engine Coolant Temperature Circuit Range / Performance Problem

DESCRIPTION

A thermistor is built into the engine coolant temperature sensor, of which the resistance value varies according to the engine coolant temperature.
The structure of the sensor and its connection to the ECM (included in the hybrid vehicle control ECU) are similar to the intake air temperature sensor.






MONITOR DESCRIPTION

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 set.

Engine coolant temperature sensor soak monitor

After a warmed up engine is started, if the engine coolant temperature sensor value does not change when the 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 set.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

Engine coolant temperature sensor cold start monitor:





Engine coolant temperature sensor soak monitor:





TYPICAL MALFUNCTION THRESHOLDS

Engine coolant temperature sensor cold start monitor:





Engine coolant temperature sensor soak monitor:





COMPONENT OPERATING RANGE





INSPECTION PROCEDURE
HINT:
- If any of DTCs P0115, P0117, P0118 or P0125 are set simultaneously with DTC P0116, the engine coolant temperature sensor may have an open or a short circuit. Troubleshoot those DTCs first.
- Read freeze frame data using the Techstream. The ECM (included in the hybrid vehicle control ECU) records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0116)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read the DTCs.
Result:





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

B -- GO TO DTC CHART Diagnostic Trouble Code Descriptions
A -- Continue to next step.
2. INSPECT THERMOSTAT
(a) Remove the thermostat Removal.
(b) Check the valve opening temperature of the thermostat.
Standard:
80 to 84°C (176 to 183°F)
HINT: In addition to the above check, confirm that the valve is completely closed when the temperature is below the standard.
(c) Reinstall the thermostat Installation.
NG -- REPLACE THERMOSTAT
OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR