Diagnosis Procedure

WARNING: This page is about a different car, the 2009 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.

CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E9. Refer to Ground Inspection in "CIRCUIT INSPECTION ".
Is the inspection result normal?

YES: GO TO 2.

NO: Repair or replace ground connection.

CHECK ECT SENSOR POWER SUPPLY CIRCUIT

Disconnect engine coolant temperature (ECT) sensor harness connector.
Turn ignition switch ON.
Check the voltage between ECT sensor harness connector and ground.

TERMINAL CONNECTOR REFERENCE CHART

ECT sensor		Ground	Voltage
Connector	Terminal	Ground	Voltage
F11	1	Ground	Approx. 5 V

Fig 1: Checking Voltage Between ECT Sensor Harness Connector And Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

Is the inspection result normal?

YES: GO TO 3.

NO: Repair open circuit, short to ground or short to power in harness or connectors.

CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

Turn ignition switch OFF.
Disconnect ECM harness connector.

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

TERMINAL CONNECTOR REFERENCE CHART

ECT sensor		ECM		Continuity
Connector	Terminal	Connector	Terminal	Continuity
F11	2	F13	52	Existed

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

Is the inspection result normal?

YES: GO TO 4.

NO: Repair open circuit, short to ground or short to power in harness or connectors.

CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to "COMPONENT INSPECTION ".

Is the inspection result normal?

YES: GO TO 5.

NO: Replace engine coolant temperature sensor.
CHECK INTERMITTENT INCIDENT
Refer to "INTERMITTENT INCIDENT ".

: INSPECTION END