Diagnosis Procedure

WARNING: This page is about a different car, the 2018 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.

CHECK DTC PRIORITY
If DTC P1078 or P1084 is displayed with DTC P0643, first perform the confirmation procedure (trouble diagnosis) for DTC P0643.

Is applicable DTC detected?

YES

Perform diagnosis of applicable. Refer to DTC Description .

NO

GO TO 2.

CHECK EXHAUST VALVE TIMING (EVT) CONTROL POSITION SENSOR POWER SUPPLY

Disconnect EVT control position sensor harness connector.
Turn ignition switch ON.

Check the voltage between EVT control position sensor harness connector and ground.

DTC	+			-	Voltage (V)
	EVT control position sensor
	Bank	Connector	Terminal
P1078	1	F82	1	Ground	Approx. 5
P1084	2	F81	1

Is the inspection result normal?

YES

GO TO 4.

GO TO 3.

CHECK EVT CONTROL POSITION SENSOR POWER SUPPLY CIRCUIT

Turn ignition switch OFF.
Disconnect ECM harness connector.

Check the continuity between EVT control position sensor harness connector and ECM harness connector.

DTC	EVT control position sensor			ECM		Continuity
	Bank	Connector	Terminal	Connector	Terminal
P1078	1	F82	1	F13	28	Existed
P1084	2	F81	1

Is the inspection result normal?

YES

INSPECTION END

Repair or replace error-detected parts.

CHECK EVT CONTROL POSITION SENSOR GROUND CIRCUIT

Turn ignition switch OFF.
Disconnect ECM harness connector.

Check the continuity between EVT control position sensor harness connector and ECM harness connector.

DTC	EVT control position sensor			ECM		Continuity
	Bank	Connector	Terminal	Connector	Terminal
P1078	1	F82	2	F13	40	Existed
P1084	2	F81	2

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

Is the inspection result normal?

YES

GO TO 5.

Repair open circuit, short to ground or short to power in harness or connectors.

CHECK EVT CONTROL POSITION SENSOR INPUT SIGNAL CIRCUIT

Check the continuity between exhaust valve timing control position sensor harness connector and ECM harness connector.

DTC	+			-		Continuity
	EVT control position sensor			ECM
	Bank	Connector	Terminal	Connector	Terminal
P1078	1	F82	3	F13	37	Existed
P1084	2	F81	3		39

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

Is the inspection result normal?

YES

GO TO 6.

Repair open circuit, short to ground or short to power in harness or connectors.

CHECK EVT CONTROL POSITION SENSOR
Check exhaust valve timing control position sensor. Refer to Component Inspection .

Is the inspection result normal?

YES

GO TO 7.

NO

Replace malfunctioning EVT control position sensor. Refer to Exploded View .
CHECK CKP SENSOR
Check Crankshaft position sensor. Refer to Component Inspection .

Is the inspection result normal?

YES

GO TO 8.

NO

Replace crankshaft position sensor. Refer to Exploded View .
CHECK CMP SENSOR
Check camshaft position sensor. Refer to Component Inspection .

Is the inspection result normal?

YES

GO TO 9.

NO

Replace malfunctioning camshaft position sensor. Refer to Exploded View .

CHECK CAMSHAFT (EXH)

Check the following.

Accumulation of debris to the signal plate of camshaft rear end

Courtesy of NISSAN NORTH AMERICA, INC.

Chipping signal plate of camshaft rear end

Is the inspection result normal?

YES

INSPECTION END

Remove debris and clean the signal plate of camshaft rear end or replace camshaft. Refer to Removal and Installation .