Infiniti QX56 (JA60). Manual - part 353

EC-64

< FUNCTION DIAGNOSIS >

[VK56DE]

ON BOARD DIAGNOSTIC (OBD) SYSTEM

Item

DIAGNOSTIC TEST MODE

WORK 

SUP-

PORT

SELF-DIAGNOSTIC 

RESULTS

DATA 

MONI-

TOR

ACTIVE 

TEST

DTC & SRT

CONFIRMATION

DTC*1

FREEZE 

FRAME 
DATA*2

SRT 

STATUS

DTC 

WORK 

SUP-

PORT

E

N

GINE

 CO

NTRO

L COMPONENT 

P

ARTS

INPUT

Crankshaft position sensor (POS)

×

×

×

Camshaft position sensor (PHASE)

×

×

×

Mass air flow sensor

×

×

Engine coolant temperature sensor

×

×

×

×

Air fuel ratio (A/F) sensor 1

×

×

×

×

Heated oxygen sensor 2

×

×

×

×

Wheel sensor

×

×

×

Accelerator pedal position sensor

×

×

Throttle position sensor

×

×

×

Fuel tank temperature sensor

×

×

×

EVAP control system pressure sen-
sor

×

×

Intake air temperature sensor

×

×

×

Knock sensor

×

Refrigerant pressure sensor

×

Closed throttle position switch (ac-
celerator pedal position sensor sig-
nal)

×

Air conditioner switch

×

Park/neutral position (PNP) signal

×

×

Stop lamp switch

×

×

Power steering pressure sensor

×

×

Battery voltage

×

Load signal

×

Intake valve timing control position 
sensor

×

×

Fuel level sensor

×

×

Battery current sensor

×

×

ICC steering switch

×

×

ASCD steering switch

×

×

ICC brake switch

×

×

ASCD brake switch

×

×

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-65

< FUNCTION DIAGNOSIS >

[VK56DE]

C

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X: Applicable
*1: This item includes 1st trip DTCs.
*2: This mode includes 1st trip freeze frame data or freeze frame data. The items appear on CONSULT-III screen in freeze frame data
mode only if a 1st trip DTC or DTC is detected. For details, refer to “Freeze Frame Data and 1st Trip Freeze Frame Data”.
*3: Always “CMPLT” is displayed.

WORK SUPPORT MODE

Work Item

E

NG

IN

E

 CON

T

RO

L COMPONENT 

P

ARTS

OUTPUT

Fuel injector

×

×

Power transistor (Ignition timing)

×

×

Throttle control motor relay

×

×

Throttle control motor

×

EVAP canister purge volume con-
trol solenoid valve

×

×

×

×

Air conditioner relay

×

Fuel pump relay

×

×

×

Cooling fan relay

×

×

×

Air fuel ratio (A/F) sensor 1 heater

×

×

×*3

Heated oxygen sensor 2 heater

×

×

×*3

EVAP canister vent control valve

×

×

×

×

Intake valve timing control solenoid 
valve

×

×

×

Alternator

×

×

Calculated load value

×

×

Item

DIAGNOSTIC TEST MODE

WORK 

SUP-

PORT

SELF-DIAGNOSTIC 

RESULTS

DATA 

MONI-

TOR

ACTIVE 

TEST

DTC & SRT

CONFIRMATION

DTC*1

FREEZE 

FRAME 
DATA*2

SRT 

STATUS

DTC 

WORK 

SUP-

PORT

WORK ITEM

CONDITION

USAGE

FUEL PRESSURE RELEASE

• FUEL PUMP WILL STOP BY TOUCHING “START” DUR-

ING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS.

When releasing fuel pressure from 
fuel line

IDLE AIR VOL LEARN

• THE IDLE AIR VOLUME THAT KEEPS THE ENGINE 

WITHIN THE SPECIFIED RANGE IS MEMORIZED IN 
ECM.

When learning the idle air volume

SELF-LEARNING CONT

• THE COEFFICIENT OF SELF-LEARNING CONTROL 

MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT.

When clearing the coefficient of 
self-learning control value

EC-66

< FUNCTION DIAGNOSIS >

[VK56DE]

ON BOARD DIAGNOSTIC (OBD) SYSTEM

*: This function is not necessary in the usual service procedure.

SELF-DIAG RESULTS MODE

Self Diagnostic Item

Regarding items of DTC and 1st trip DTC, refer to 

EC-459, "DTC Index"

.

Freeze Frame Data and 1st Trip Freeze Frame Data

EVAP SYSTEM CLOSE

CLOSE THE EVAP CANISTER VENT CONTROL VALVE IN 
ORDER TO MAKE EVAP SYSTEM CLOSE UNDER THE 
FOLLOWING CONDITIONS.
• IGN SW ON
• ENGINE NOT RUNNING
• AMBIENT TEMPERATURE IS ABOVE 0

°C (32°F).

• NO VACUUM AND NO HIGH PRESSURE IN EVAP SYS-

TEM

•  FUEL TANK TEMP. IS MORE THAN 0

°C (32°F).

• WITHIN 10 MINUTES AFTER STARTING “EVAP SYS-

TEM CLOSE”

• WHEN TRYING TO EXECUTE “EVAP SYSTEM CLOSE” 

UNDER THE CONDITION EXCEPT ABOVE, CONSULT-
III WILL DISCONTINUE IT AND DISPLAY APPROPRI-
ATE INSTRUCTION.
NOTE:
WHEN STARTING ENGINE, CONSULT-III MAY DIS-
PLAY “BATTERY VOLTAGE IS LOW. CHARGE BAT-
TERY”, EVEN IN USING CHARGED BATTERY.

When detecting EVAP vapor leak 
point of EVAP system

VIN REGISTRATION

• IN THIS MODE, VIN IS REGISTERED IN ECM

When registering VIN in ECM

TARGET IDLE RPM ADJ*

• IDLE CONDITION

When setting target idle speed

TARGET IGN TIM ADJ*

• IDLE CONDITION

When adjusting target ignition tim-
ing

WORK ITEM

CONDITION

USAGE

Freeze frame data 

item*

Description

DIAG TROUBLE 
CODE
[PXXXX]

• The engine control component part/control system has a trouble code, it is displayed as PXXXX. (Refer to 

EC-459, "DTC Index"

.)

FUEL SYS-B1

• “Fuel injection system status” at the moment a malfunction is detected is displayed.
• One mode in the following is displayed.

Mode2: Open loop due to detected system malfunction
Mode3: Open loop due to driving conditions (power enrichment, deceleration enleanment)
Mode4: Closed loop - using oxygen sensor(s) as feedback for fuel control
Mode5: Open loop - has not yet satisfied condition to go to closed loop

FUEL SYS-B2

CAL/LD VALUE [%]

• The calculated load value at the moment a malfunction is detected is displayed.

COOLANT TEMP
[

°C] or [°F]

• The engine coolant temperature at the moment a malfunction is detected is displayed.

L-FUEL TRM-B1 [%]

• “Long-term fuel trim” at the moment a malfunction is detected is displayed.
• The long-term fuel trim indicates much more gradual feedback compensation to the base fuel schedule than 

short-term fuel trim.

L-FUEL TRM-B2 [%]

S-FUEL TRM-B1 [%]

• “Short-term fuel trim” at the moment a malfunction is detected is displayed.
• The short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel sched-

ule.

S-FUEL TRM-B2 [%]

ENGINE SPEED [rpm] • The engine speed at the moment a malfunction is detected is displayed.

VEHICL SPEED
[km/h] or [mph]

• The vehicle speed at the moment a malfunction is detected is displayed.

ABSOL TH-P/S
[%]

• The throttle valve opening at the moment a malfunction is detected is displayed.

B/FUEL SCHDL 
[msec]

• The base fuel schedule at the moment a malfunction is detected is displayed.

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-67

< FUNCTION DIAGNOSIS >

[VK56DE]

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*: The item is the same as that of 1st trip freeze frame data.

DATA MONITOR MODE

Monitored Item

×: Applicable

INT/A TEMP SE
[

°C] or [°F]

• The intake air temperature at the moment a malfunction is detected is displayed.

INT MANI PRES [kPa]

• Always a certain value is displayed.
• These items are not efficient JA60 models.

COMBUST CONDI-
TION

Freeze frame data 

item*

Description

Monitored item 

[Unit]

ECM IN-

PUT SIG-

NALS

MAIN 

SIGNALS

Description

Remarks

ENG SPEED [rpm]

×

×

• Indicates the engine speed computed 

from the signal of the crankshaft position 
sensor (POS) and camshaft position 
sensor (PHASE).

• Accuracy becomes poor if engine 

speed drops below the idle rpm.

• If the signal is interrupted while the en-

gine is running, an abnormal value may 
be indicated.

MAS A/F SE-B1 [V]

×

×

• The signal voltage of the mass air flow 

sensor is displayed.

• When the engine is stopped, a certain 

value is indicated.

• When engine is running specification 

range is indicated in “SPEC”.

B/FUEL SCHDL 
[msec]

×

×

• Base fuel schedule indicates the fuel in-

jection pulse width programmed into 
ECM, prior to any learned on board cor-
rection.

• When engine is running specification 

range is indicated in “SPEC”.

A/F ALPHA-B1 [%]

• The mean value of the air-fuel ratio feed-

back correction factor per cycle is indi-
cated.

• When the engine is stopped, a certain 

value is indicated.

• When engine is running specification 

range is indicated in “SPEC”.

• This data also includes the data for the 

air-fuel ratio learning control.

A/F ALPHA-B2 [%]

COOLAN TEMP/S 
[

°C] or [°F]

×

×

• The engine coolant temperature (deter-

mined by the signal voltage of the engine 
coolant temperature sensor) is dis-
played.

• When the engine coolant temperature 

sensor is open or short-circuited, ECM 
enters fail-safe mode. The engine cool-
ant temperature determined by the 
ECM is displayed.

A/F SEN1 (B1) [V]

×

×

• The A/F signal computed from the input 

signal of the A/F sensor 1 is displayed.

A/F SEN1 (B2) [V]

×

×

HO2S2 (B1) [V]

×

×

• The signal voltage of the heated oxygen 

sensor 2 is displayed.

HO2S2 (B2) [V]

×

×

HO2S2 MNTR (B1) 
[RICH/LEAN]

×

• Display of heated oxygen sensor 2 sig-

nal:
RICH: means the amount of oxygen after 
three way catalyst is relatively small.
LEAN: means the amount of oxygen af-
ter three way catalyst is relatively large.

• When the engine is stopped, a certain 

value is indicated.

HO2S2 MNTR (B2) 
[RICH/LEAN]

×

VHCL SPEED SE 
[km/h] or [mph]

×

×

• The vehicle speed computed from the 

vehicle speed signal sent from combina-
tion meter is displayed.

BATTERY VOLT [V]

• The power supply voltage of ECM is dis-

played.

ACCEL SEN 1 [V]

• The accelerator pedal position sensor 

signal voltage is displayed.

• ACCEL SEN 2 signal is converted by 

ECM internally. Thus, it differs from 
ECM terminal voltage signal.

ACCEL SEN 2 [V]