Infiniti QX56 (JA60). Manual - part 386

EC-196

< COMPONENT DIAGNOSIS >

[VK56DE]

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE

OK or NG

OK

>> GO TO 12.

NG

>> GO TO 11.

11.

DETECT MALFUNCTIONING PART

Check the following.

• Fuel pump and circuit (Refer to 

EC-399, "Diagnosis Procedure"

.)

• Fuel pressure regulator (Refer to 

EC-489, "Fuel Pressure Check"

.)

• Fuel lines

• Fuel filter for clogging

>> Repair or replace.

12.

CHECK IGNITION TIMING

Check the following items. Refer to 

EC-13, "Basic Inspection"

.

OK or NG

OK

>> GO TO 13.

NG

>> Follow the 

EC-13, "Basic Inspection"

.

13.

CHECK A/F SENSOR 1 INPUT SIGNAL

1.  Turn ignition switch OFF.

2. Disconnect A/F sensor 1 harness connector.

3. Disconnect ECM harness connector.

4. Check harness continuity between the following terminals.

Refer to Wiring Diagram.

5. Check harness continuity between the following terminals and ground.

Refer to Wiring Diagram.

Items

Specifications

Target idle speed

650 

± 50 rpm (in P or N position)

Ignition timing

15 

± 5° BTDC (in P or N position)

A/F sensor 1 terminal

ECM terminal

Bank 1

1

35

2

56

Bank 2

1

16

2

75

Continuity should exist.

Bank 1

Bank 2

A/F sensor 1 terminal

ECM terminal

A/F sensor 1 terminal

ECM terminal

1

35

1

16

2

56

2

75

BBIA0376E

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE

EC-197

< COMPONENT DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

6. Also check harness for short to power.
OK or NG

OK

>> GO TO 14.

NG

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

14.

CHECK A/F SENSOR 1 HEATER

Refer to 

EC-97, "Component Inspection"

.

OK or NG

OK

>> GO TO 16.

NG

>> GO TO 15.

15.

REPLACE AIR FUEL RATIO (A/F) SENSOR 1

Replace malfunctioning air fuel ratio (A/F) sensor 1.

CAUTION:

• Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m (1.6

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

• Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sensor

Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.

>> INSPECTION END

16.

CHECK MASS AIR FLOW SENSOR

 With CONSULT-III

Check mass air flow sensor signal in “DATA MONITOR” mode with CONSULT-III.

 With GST

Check mass air flow sensor signal in Service $01 with GST.

OK or NG

OK

>> GO TO 17.

NG

>> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or

ground. Refer to 

EC-104

.

17.

CHECK SYMPTOM MATRIX CHART

Check items on the rough idle symptom in 

EC-477, "Symptom Matrix Chart"

.

OK or NG

OK

>> GO TO 18.

NG

>> Repair or replace.

18.

ERASE THE 1ST TRIP DTC

Some tests may cause a 1st trip DTC to be set.

Erase the 1st trip DTC from the ECM memory after performing the tests. Refer to 

EC-459, "DTC Index"

.

>> GO TO 19.

19.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-35, "How to Check Terminal"

 and 

GI-38, "Intermittent Incident"

.

>> INSPECTION END

Continuity should not exist.

3.0 - 9.0 g·m/sec:

at idling

9.0 - 28.0 g·m/sec:

at 2,500 rpm

3.0 - 9.0 g·m/sec:

at idling

9.0 - 28.0 g·m/sec:

at 2,500 rpm

EC-198

< COMPONENT DIAGNOSIS >

[VK56DE]

P0327, P0328, P0332, P0333 KS

P0327, P0328, P0332, P0333 KS

Component Description

INFOID:0000000005149214

The knock sensor is attached to the cylinder block. It senses engine

knocking using a piezoelectric element. A knocking vibration from

the cylinder block is sensed as vibrational pressure. This pressure is

converted into a voltage signal and sent to the ECM.

On Board Diagnosis Logic

INFOID:0000000005149215

The MIL will not light up for these self-diagnoses.

DTC Confirmation Procedure

INFOID:0000000005149216

NOTE:

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting the next step.
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.
TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 10 V at idle.

1. Start engine and run it for at least 5 seconds at idle speed.

2. Check 1st trip DTC.

3. If 1st trip DTC is detected, go to 

EC-198, "Diagnosis Procedure"

Diagnosis Procedure

INFOID:0000000005149217

1.

CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-I

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check resistance between ECM terminals 15, 36 and ground. Refer to Wiring Diagram.

NOTE:

It is necessary to use an ohmmeter which can measure more than 10 M

Ω.

PBIB0021E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0327
0327
(bank 1)

Knock sensor circuit low in-
put

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

• Harness or connectors

(The sensor circuit is open or shorted.)

• Knock sensor

P0332
0332
(bank 2)

P0328
0328
(bank 1)

Knock sensor circuit high in-
put

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

P0333
0333
(bank 2)

Resistance: Approximately 532 - 588 k

Ω [at 20°C (68°F)]

P0327, P0328, P0332, P0333 KS

EC-199

< COMPONENT DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

4. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 5.

NG

>> GO TO 2.

2.

CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-II

1. Disconnect knock sensor harness connector.

2. Check harness continuity between ECM terminal 15 and knock

sensor (bank1) terminal 1, ECM terminal 36 and knock sensor

(bank 2) terminal 1. 

Refer to Wiring Diagram.

3. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 4.

NG

>> GO TO 3.

3.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors F26, F101

• Harness for open or short between ECM and knock sensor

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

4.

CHECK KNOCK SENSOR

Refer to 

EC-200, "Component Inspection"

.

OK or NG

OK

>> GO TO 5.

NG

>> Replace malfunctioning knock sensor.

5.

CHECK GROUND CONNECTIONS

Loosen and retighten three ground screws on the body.

Refer to 

EC-85, "Ground Inspection"

.

OK or NG

OK

>> GO TO 6.

NG

>> Repair or replace ground connections.

6.

CHECK KNOCK SENSOR SHIELD CIRCUIT FOR OPEN AND SHORT

1. Disconnect knock sensor harness connector.

2. Check harness continuity between knock sensor terminal 2 and ground. Refer to Wiring Diagram.

3. Also check harness for short to power.
OK or NG

OK

>> GO TO 8.

NG

>> GO TO 7.

Continuity should exist.

PBIB0021E

BBIA0354E

Continuity should exist.