Infiniti FX35, FX50 (S51). Manual - part 655

P0037, P0038, P0057, P0058 HO2S2 HEATER

EC-161

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

YES

>> GO TO 5.

NO

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

5.

CHECK HEATED OXYGEN SENSOR 2 HEATER

Refer to 

EC-161, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> GO TO 6.

6.

REPLACE HEATED OXYGEN SENSOR 2

Replace malfunctioning heated oxygen sensor 2.

CAUTION:

• Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7

in) onto a hard surface such as a concrete floor; use a new one.

• Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread

Cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant
(commercial service tool).

>> INSPECTION END

7.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005236760

1.

CHECK HEATED OXYGEN SENSOR 2 (HO2S2) HEATER

1.

Turn ignition switch OFF.

2.

Disconnect HO2S2 harness connector.

3.

Check resistance between HO2S2 terminals as follows.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 2.

2.

REPLACE HEATED OXYGEN SENSOR 2

Replace malfunctioning heated oxygen sensor 2.

CAUTION:

• Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7

in) onto a hard surface such as a concrete floor; use a new one.

• Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread

Cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant
(commercial service tool).

>> INSPECTION END

Terminal

Resistance

2 and 3

3.4 - 4.4 

Ω

 [at 25

°

C (77

°

F)]

1 and 2, 3, 4

∞

 

Ω

(Continuity should not exist)

4 and 1, 2, 3

EC-162

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P0075, P0081 IVT CONTROL SOLENOID VALVE

P0075, P0081 IVT CONTROL SOLENOID VALVE

Description

INFOID:0000000005236761

Intake valve timing control solenoid valve is activated by ON/OFF
pulse duty (ratio) signals from the ECM.
The intake valve timing control solenoid valve changes the oil
amount and direction of flow through intake valve timing control unit
or stops oil flow.
The longer pulse width advances valve angle.
The shorter pulse width retards valve angle.
When ON and OFF pulse widths become equal, the solenoid valve
stops oil pressure flow to fix the intake valve angle at the control
position.

DTC Logic

INFOID:0000000005236762

DTC DETECTION 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.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Start engine and let it idle for 5 seconds.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-162, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005236763

1.

CHECK INTAKE VALVE TIMING (IVT) CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect IVT control solenoid valve harness connector.

3.

Turn ignition switch ON.

4.

Check the voltage between IVT control solenoid valve harness connector and ground.

PBIB1842E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0075

Intake valve timing control so-
lenoid valve (bank 1) circuit

An improper voltage is sent to the ECM 
through intake valve timing control solenoid 
valve.

• Harness or connectors

(Intake valve timing control solenoid 
valve circuit is open or shorted.)

• Intake valve timing control solenoid 

valve

P0081

Intake valve timing control so-
lenoid valve (bank 2) circuit

DTC

IVT control solenoid valve

Ground

Voltage

Bank

Connector

Terminal

P0075

1

F28

2

Ground

Battery voltage

P0081

2

F29

2

P0075, P0081 IVT CONTROL SOLENOID VALVE

EC-163

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 2.

2.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors E3, F1
• Harness for open or short between IVT control solenoid valve and IPDM E/R

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

3.

CHECK IVT CONTROL SOLENOID VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check the continuity between IVT control solenoid valve harness connector and ECM harness connector.

4.

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.

4.

CHECK IVT CONTROL SOLENOID VALVE

Refer to 

EC-163, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace malfunctioning IVT control solenoid valve.

5.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005236764

1.

CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE-I

1.

Turn ignition switch OFF.

2.

Disconnect intake valve timing control solenoid valve harness connector.

3.

Check resistance between intake valve timing control solenoid valve terminals as follows.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Replace malfunctioning intake valve timing control solenoid valve.

2.

CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE-II

1.

Remove intake valve timing control solenoid valve.

DTC

IVT control solenoid valve

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

P0075

1

F28

1

F101

18

Existed

P0081

2

F29

1

29

Terminals

Resistance

1 and 2

7.0 - 7.7 

Ω

 [at 20

°

C (68

°

F)]

1 or 2 and ground

∞Ω

(Continuity should not exist)

EC-164

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P0075, P0081 IVT CONTROL SOLENOID VALVE

2.

Apply 12 V between intake valve timing control solenoid valve
terminals 1 and 2, and then interrupt it. Check that the plunger
moves as shown in the figure.

CAUTION:

Never apply 12 V continuously for 5 seconds or more.
Doing so may result in damage to the coil in intake valve
timing control solenoid valve.
NOTE:
Always replace O-ring when intake valve timing control
solenoid valve is removed.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace malfunctioning intake valve timing control solenoid valve.

JMBIA0079ZZ