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Home >> Toyota >> 2004 >> Matrix Base, FWD, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (SFI) - Diagnostics (1ZZ-FE) >> DTC P0115: Engine Coolant Temperature Circuit, DTC P0117: Engine Coolant Temperature Circuit Low Input, DTC P0118: Engine Coolant Temperature Circuit High Input >> Circuit Description
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Circuit Description

A thermistor is built in the engine coolant temperature sensor and changes the resistance value according to the engine coolant temperature.

The structure of the sensor and connection to the ECM is the same as those of the intake air temperature sensor.

NOTE:

If the ECM detects the DTC P0115, P0117 or P0118, it operates the fail-safe function in which the engine coolant temperature is fixed at 80 °C (176 °F).

Fig 1: DTC Table
G02914498Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NOTE:

After confirming DTC P0115, P0117or P0118, confirm the engine coolant temperature in the "DIAGNOSIS/ENHANCED OBD I I/DATA LIST/ALL" using the hand-held tester or the OBD II scan tool.

ENGINE COOLANT TEMPERATURE CONFIRMATION

Temperature Displayed Malfunction
-40°C (-40°F) Open circuit
140°C(284°F)or more Short circuit