Toyota 2GR-FE Manual page 315

DTC P0116
DESCRIPTION
A thermistor is built into the Engine Coolant Temperature (ECT) sensor, of which the resistance value
varies according to the ECT.
The structure of the sensor and its connection to the ECM are the same as those of the Intake Air
Temperature (IAT) sensor.
DTC No.
ECTs as listed below are nearly same (2 trip detection
logic):
–
–
P0116
ECTs as listed below are nearly same when engine is
started at higher than 60°C (140°F) of ECT (2 trip
detection logic)
–
–
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 drops, the resistance of the
thermistor increases. When the temperature rises, 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:
(1)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 remains within 3°C (5.4°F) of the starting temperature, the DTC is set (2 trip
detection logic).
(2)Upon starting the engine, the ECT is over 60°C (140°F). If, after driving for 250 seconds, the ECM
remains within 1°C (1.8°F) of the starting temperature, the DTC is set (6 trip detection logic).
MONITOR STRATEGY
Related DTCs
Required Sensors/Components (Main)
Required Sensors/Components (Sub)
Frequency of Operation
Duration
MIL Operation
Sequence of Operation
TYPICAL ENABLING CONDITIONS
All:
Monitor runs whenever following DTCs are not present
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
Engine Coolant Temperature Circuit Range /
Performance Problem
DTC Detection Condition
ECT when engine is started at lower than 60°C
(140°F) of ECT
ECT when engine is warmed up
ECT when engine is stopped after driving
ECT when engine is started at lower than 60°C
(140°F) of ECT
• Thermostat
• ECT sensor
P0116: Engine coolant temperature sensor rationality (ECT sensor
cold start monitor)
P0116: Engine coolant temperature sensor rationality (ECT sensor
soak monitor)
Engine coolant temperature (ECT) sensor
-
Once per driving cycle
10
2 driving cycles
None
P0100 - P0103 (MAF sensor)
ES–159
Trouble Area
ES