Advertisement
Water Temperature Sensor(WTS) Circuit Malfunction
DTC
P0115
Water Temperature Sensor(WTS) Circuit Malfunction [Except Europe]
P0116
Water Temperature Sensor(WTS) Circuit Malfunction - Range/Performance
P0117
Water Temperature Sensor(WTS) Circuit Low Voltage
P0118
Water Temperature Sensor(WTS) Circuit High Voltage or Open circuit
P0125
Insufficient Coolant Temperature for Closed Loop Fuel Control
DESCRIPTION
The Water Temperature sensor(WTS) is located in a coolant passage of the cylinder head. The WTS
sensor is a variable resistor whose resistance changes as the temperature of the engine coolant flowing
past the sensor changes. When the water temperature is low, the sensor resistance is high; when the
water temperature is high, the sensor resistance is low. ECU checks WTS voltage fifty times per second
and uses the information to help adjust the fuel injector pulse width and ignition timing. When the
temperature sensed is very cold, the ECU enriches the fuel mixture.
TROUBLESHOOTING GUIDE
Background
a. The Water temperature sensor converts the water temperature
to a voltage and outputs it.
b. ECU checks whether the voltage is within a specified range. In
addition, it checks that the water temperature (signal) does not
drop while the engine is warming up.
Malfunction; out-of-range
a. Sensor output voltage has continued to be 4.6V or higher
[corresponding to water temperature of -45°C (-49°F) or lower]
for 4 sec.
b. Sensor output voltage has continued to be 0.1V or lower
[corresponding to water temperature of 140°C (284°F) or higher]
for 4 sec.
Malfunction; out-of-range
a. Sensor output voltage increased from a value lower than 1.6V to
a value higher than 1.6V [Water temperature decreases from
higher than 40°C (104°F) temperature to lower than 40°C
(104°F) temperature.].
b. Sensor output voltage has continued to be 1.6V or higher for 5
min.
Judgment Criteria, Proper Performance
a. The Water Temperature is approx. 40°C (104°F) or less after
starting sequence is completed.
b. Approx. 60 - 300 seconds have passed for the engine water
temperature to rise to about 40°C (104°F) after starting
sequence was completed.
DTC detection condition
Diagnostic item
a. Water Temperature sensor
failed.
b. Open or shorted Water
Temperature sensor circuit, or
loose connector.
c. ECU failed.
Probable cause
Advertisement
