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.

HINT:

When any of DTCs P0115, P0117 and P0118 are set, the ECM enters fail-safe mode. During fail-safe mode, the ECT is estimated to be 80°C (176°F) by the ECM. Fail-safe mode continues until a pass condition is detected.

DTC No.

Proceed To

DTC Detection Conditions

Trouble Areas

P0115

Step 1

Open or short in Engine Coolant Temperature (ECT) sensor circuit for 0.5 seconds (1 trip detection logic)

• Open or short in ECT sensor circuit

• ECM

P0117

Step 4

Short in Engine Coolant Temperature (ECT) sensor circuit for 0.5 seconds (1 trip detection logic)

• Short in ECT sensor circuit

• ECM

P0118

Step 2

Open in Engine Coolant Temperature (ECT) sensor circuit for 0.5 seconds (1 trip detection logic)

• Open in ECT sensor circuit

When any of these DTCs are set, check the ECT by selecting the following menu items on an intelligent tester: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.

Temperature Displayed

Malfunctions

-40°C (-40° F)

Open circuit

140°C (284°F) or higher

Short circuit

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