Diagnosis Procedure

WARNING: This page is about a different car, the 2019 Infiniti QX60. However, it is still accessible from the selected car via links, so may be relevant.

CHECK ECT SENSOR POWER SUPPLY

Turn ignition switch OFF.
Disconnect engine coolant temperature (ECT) sensor harness connector.
Turn ignition switch ON.

Check the voltage between ECT sensor harness connector and ground.

+		-	Voltage (Approx.)
ECT sensor
Connector	Terminal
F61	1	Ground	5 V

Is the inspection result normal?

YES

GO TO 3.

GO TO 2.

CHECK ECT SENSOR POWER SUPPLY CIRCUIT

Turn ignition switch OFF.
Disconnect ECM harness connector.

Check the continuity between ECT sensor harness connector and ECM harness connector.

ECT sensor		ECM		Continuity
Connector	Terminal	Connector	Terminal	Continuity
F61	1	F78	56	Existed

Also check harness for short to power and short to ground.

Is the inspection result normal?

YES

Perform trouble diagnosis for ECM power supply circuit. Refer to Diagnosis Procedure .

Repair or replace error-detected parts.

CHECK ECT SENSOR GROUND CIRCUIT

Turn ignition switch OFF.
Disconnect ECM harness connector.

Check the continuity between ECT sensor harness connector and ECM harness connector.

ECT sensor		ECM		Continuity
Connector	Terminal	Connector	Terminal	Continuity
F61	2	F79	100	Existed

Also check harness for short to power.

Is the inspection result normal?

YES

GO TO 4.

Repair or replace error-detected parts.

CHECK ECM GROUND CIRCUIT

Check the continuity between ECM harness connector and ground.

ECM		--	Continuity
Connector	Terminal
F78	2	Ground	Existed
	7
F79	87
	88
	95
E32	199
	201
	204

Also check harness for short to power.

Is the inspection result normal?

YES

GO TO 5.

Repair or replace error-detected parts.

CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to Component Inspection (Engine Coolant Temperature Sensor) .

Is the inspection result normal?

YES

INSPECTION END

NO

Replace engine coolant temperature sensor. Refer to Exploded View .