ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION[AJ (3.0L Duratec)]

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Note

•  Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL.)

Resistance Inspection

1.  Disconnect the ECT sensor connector.

2.  Remove the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION[AJ (3.0L Duratec)].)

3.  Place the detection part of the ECT sensor in water and while gradually increasing the water temperature, measure the resistance between the ECT sensor terminals.

•  If it is not within the specification, replace the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION[AJ (3.0L Duratec)].)

•  If the monitor item status/specification (reference) is not within the specification, even though the resistance is within the specification, perform the “Circuit Open/Short Inspection”.

ECT sensor characteristics graph (reference)

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Circuit Open/Short Inspection

1.  Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION[AJ (3.0L Duratec)].)

2.  Inspect the following wiring harness for open or short (continuity check).

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Open circuit

•  If there is no continuity, the circuit is open. Repair or replace the harness.

―  ECT sensor terminal A and PCM terminal 38

―  ECT sensor terminal B and PCM terminal 91

Short circuit

•  If there is continuity, the circuit is shorted. Repair or replace the harness.

―  ECT sensor terminal A and body ground

―  ECT sensor terminal A and power supply

―  ECT sensor terminal B and power supply