Infiniti FX35, FX50 (S51). Manual - part 706

P1078, P1084 EVT CONTROL POSITION SENSOR

EC-365

< DTC/CIRCUIT DIAGNOSIS >

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P1078, P1084 EVT CONTROL POSITION SENSOR

Description

INFOID:0000000005236956

Exhaust valve timing (EVT) control position sensor detects the con-
cave groove of the exhaust camshaft rear end. 
This sensor signal is used for sensing a position of the exhaust cam-
shaft.
This sensor uses a Hall IC.
Based on the position of the exhaust camshaft, ECM controls
exhaust valve timing control magnet retarder to optimize the shut/
open timing of exhaust valve for the driving condition.

DTC Logic

INFOID:0000000005236957

DTC DETECTION LOGIC

NOTE:
If DTC P1078 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to

EC-359, "DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Turn ignition switch OFF and wait at least 10 seconds.

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DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1078

Exhaust valve timing 
(EVT) control position 
sensor (bank 1) circuit

An excessively high or low voltage from 
the sensor is sent to ECM.

• Harness or connectors

[EVT control position sensor (bank 1) circuit is 
open or shorted)

• EVT control position sensor
• Crankshaft position (CKP) sensor
• Camshaft position (CMP) sensor (bank 1)
• Accumulation of debris to the signal pick-up 

portion of the camshaft

P1084

Exhaust valve timing 
(EVT) control position 
sensor (bank 2) circuit

• Harness or connectors

[EVT control position sensor (bank 2) circuit is 
open or shorted)
(CKP sensor circuit is shorted.)
[CMP sensor (bank 2) circuit is shorted.]
(Battery current sensor circuit is shorted.)
(APP sensor 2 circuit is shorted.)
(EVAP control system pressure sensor circuit 
is shorted.)
(Refrigerant pressure sensor circuit is short-
ed.)

• EVT control position sensor (bank 2)
• CKP sensor
• CMP sensor (bank 2)
• Battery current sensor
• Accelerator pedal position (APP) sensor
• EVAP control system pressure sensor
• Refrigerant pressure sensor
• Accumulation of debris to the signal pick-up 

portion of the camshaft

EC-366

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P1078, P1084 EVT CONTROL POSITION SENSOR

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Start engine and let it idle for 10 seconds.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-366, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005236958

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection M95. Refer to Ground Inspection in 

GI-39, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

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

1.

Disconnect EVT control position sensor harness connector.

2.

Turn ignition switch ON.

3.

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

Is the inspection result normal?

YES

>> GO TO 8.

NO-1

>> P1078: Repair open circuit, short to ground or short to power in harness or connectors.

NO-2

>> P1084: GO TO 3.

3.

CHECK EVT CONTROL POSITION SENSOR POWER SUPPLY CIRCUIT-II

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

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

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair open circuit.

4.

CHECK SENSOR POWER SUPPLY CIRCUIT

Check harness for short to power and short to ground, between the following terminals.

DTC

EVT control position sensor

Ground

Voltage (V)

Bank

Connector

Terminal

P1078

1

F4

1

Ground

Approx. 5

P1084

2

F19

1

EVT control position sensor

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

2

F19

1

F102

64

Existed

ECM

Sensor

Connector

Terminal

Name

Connector

Terminal

F101

46

Crankshaft position (CKP) sensor

F2

1

P1078, P1084 EVT CONTROL POSITION SENSOR

EC-367

< DTC/CIRCUIT DIAGNOSIS >

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Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair short to ground or short to power in harness or connectors.

5.

CHECK COMPONENTS

Check the following.
• CKP sensor (Refer to 

EC-271, "Component Inspection"

.)

• CMP sensor (bank 2) (Refer to 

EC-277, "Component Inspection"

.)

• Battery current sensor (Refer to 

EC-400, "Component Inspection"

.)

• EVAP control system pressure sensor (Refer to 

EC-313, "Component Inspection"

.)

• Refrigerant pressure sensor (Refer to 

HAC-84, "Diagnosis Procedure"

.)

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Replace malfunctioning component.

6.

CHECK APP SENSOR

Refer to 

EC-444, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 15.

NO

>> GO TO 7.

7.

REPLACE ACCELERATOR PEDAL ASSEMBLY

1.

Replace accelerator pedal assembly.

2.

Go to 

EC-445, "Special Repair Requirement"

.

>> INSPECTION END

8.

CHECK EVT CONTROL POSITION SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

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

4.

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

Is the inspection result normal?

YES

>> GO TO 9.

NO

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

F102

64

Camshaft position (CMP) sensor (bank 
2)

F18

1

EVT control position sensor (bank 2)

F19

1

Battery current sensor

E21

1

M107

103

Accelerator pedal position (APP) sensor

E112

(Without ICC)

6

E116

(With ICC)

3

107

EVAP control system pressure sensor

B252

3

111

Refrigerant pressure sensor

E77

3

ECM

Sensor

Connector

Terminal

Name

Connector

Terminal

DTC

EVT control position sensor

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

P1078

1

F4

2

F102

88

Existed

P1084

2

F19

2

EC-368

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P1078, P1084 EVT CONTROL POSITION SENSOR

9.

CHECK EVT CONTROL POSITION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

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

2.

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

Is the inspection result normal?

YES

>> GO TO 11.

NO

>> GO TO 10.

10.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors F107, F106
• Harness for open or short between EVT control position sensor and ECM

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

11.

CHECK EVT CONTROL POSITION SENSOR

Refer to 

EC-369, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 12.

NO

>> Replace malfunctioning EVT control position sensor.

12.

CHECK CKP SENSOR

Refer to 

EC-271, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 13.

NO

>> Replace CKP sensor.

13.

CHECK CMP SENSOR

Refer to 

EC-277, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 14.

NO

>> Replace malfunctioning CMP sensor.

14.

CHECK CAMSHAFT (EXH)

Check the following.
• Accumulation of debris to the signal plate of camshaft rear end
• Chipping signal plate of camshaft rear end
Is the inspection result normal?

YES

>> GO TO 15.

NO

>> Remove debris and clean the signal plate of camshaft

rear end or replace camshaft.

15.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

DTC

EVT control position sensor

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

P1078

1

F4

3

F102

58

Existed

P1084

2

F19

3

62

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