P0116

2AZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0116: Engine Coolant Temperature Circuit Range / Performance Problem
P0116 - Engine Coolant Temperature Circuit Range / Performance Problem

DESCRIPTION

Refer to DTC P0115 P0115.





MONITOR DESCRIPTION

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 becomes low, the resistance of the thermistor increases. When the temperature becomes high, the resistance drops. These variations in the resistance are reflected in the voltage output from the ECT sensor.

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 sets the DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

ECT sensor cold start monitor:

ECT sensor cold start monitor::

ECT sensor soak monitor:

ECT sensor soak monitor::

TYPICAL MALFUNCTION THRESHOLDS

ECT Sensor cold start monitor:

ECT Sensor cold start monitor::

ECT Sensor soak monitor:

ECT Sensor soak monitor::

COMPONENT OPERATING RANGE





INSPECTION PROCEDURE

HINT
- If DTC P0115, P0116, P0117, P0118 and P0125 are output simultaneously, the ECT sensor circuit may be open or shorted. Perform the troubleshooting for DTC P0115, P0117 or P0118 first.
- 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 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 OTHER DTC OUTPUT (IN ADDITION TO DTC P0116)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to the ON position and turn the Techstream on.

(c) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.

(d) Read the DTCs.

Result:





B -- GO TO DTC CHART Engine Control System - SFI System
A -- Continue to next step.

2. INSPECT THERMOSTAT

(a) Remove the thermostat Removal.

(b) Check the valve opening temperature of the thermostat.

Standard temperature:

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 Removal

OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal