Infiniti QX56 (Z62). Manual - part 522

EC-66

< SYSTEM DESCRIPTION >

[VK56VD]

DIAGNOSIS SYSTEM (ECM)

A/F ALPHA-B1

%

• The mean value of the air-fuel ratio feedback cor-

rection factor per cycle is indicated.

• When the engine is stopped, 

a certain value is indicated.

• This data also includes the 

data for the air-fuel ratio 
learning control.

• When engine is running, 

specification range is indicat-
ed in “SPEC”.

A/F ALPHA-B2

COOLAN TEMP/S

°

C or 

°

F

• The engine coolant temperature (determined by 

the signal voltage of the engine coolant tempera-
ture sensor) is displayed.

• When the engine coolant 

temperature sensor is open 
or short-circuited, ECM en-
ters fail-safe mode. The en-
gine coolant temperature 
determined by the ECM is 
displayed.

A/F SEN1 (B1)

V

• The A/F signal computed from the input signal of 

the air fuel ratio (A/F) sensor 1 is displayed.

A/F SEN1 (B2)

HO2S2 (B1)

V

• The signal voltage of the heated oxygen sensor 2 

is displayed.

HO2S2 (B2)

HO2S2 MNTR (B1)

RICH/LEAN

• Display of heated oxygen sensor 2 signal:

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

• When the engine is stopped, 

a certain value is indicated.

HO2S2 MNTR (B2)

VHCL SPEED SE

km/h or mph

• The vehicle speed computed from the vehicle 

speed signal sent from combination meter is dis-
played.

BATTERY VOLT

V

• The power supply voltage of ECM is displayed.

ACCEL SEN 1

V

• The accelerator pedal position sensor signal volt-

age is displayed.

• ACCEL SEN 2 signal is con-

verted by ECM internally. 
Thus, they differs from ECM 
terminal voltage signal.

ACCEL SEN 2

TP SEN 1-B1

V

• The throttle position sensor signal voltage is dis-

played.

• TP SEN 2-B1 signal is con-

verted by ECM internally. 
Thus, they differs from ECM 
terminal voltage signal.

TP SEN 2-B1

FUEL T/TMP SE

°

C or 

°

F

• The fuel temperature (determined by the signal 

voltage of the fuel tank temperature sensor) is dis-
played.

EVAP SYS PRES

V

• The signal voltage of EVAP control system pres-

sure sensor is displayed.

FUEL LEVEL SE

V

• The signal voltage of the fuel level sensor is dis-

played.

START SIGNAL

ON/OFF

• Indicates start signal status [ON/OFF] computed 

by the ECM according to the signals of engine 
speed and battery voltage.

• After starting the engine, 

[OFF] is displayed regard-
less of the starter signal.

CLSD THL POS

ON/OFF

• Indicates idle position [ON/OFF] computed by 

ECM according to the accelerator pedal position 
sensor signal.

AIR COND SIG

ON/OFF

• Indicates [ON/OFF] condition of the air conditioner 

switch as determined by the air conditioner signal.

PW/ST SIGNAL

ON/OFF

• [ON/OFF] condition of the power steering system 

(determined by the signal voltage of the power 
steering pressure sensor signal) is indicated.

Monitored item

Unit

Description

Remarks

DIAGNOSIS SYSTEM (ECM)

EC-67

< SYSTEM DESCRIPTION >

[VK56VD]

C

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F

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LOAD SIGNAL

ON/OFF

• Indicates [ON/OFF] condition from the electrical 

load signal.
ON: Rear window defogger switch is ON and/or 
lighting switch is in 2nd position.
OFF: Both rear window defogger switch and light-
ing switch are OFF.

IGNITION SW

ON/OFF

• Indicates [ON/OFF] condition from ignition switch 

signal.

HEATER FAN SW

ON/OFF

• Indicates [ON/OFF] condition from the blower fan 

ON signal.

BRAKE SW

ON/OFF

• Indicates [ON/OFF] condition from the stop lamp 

switch signal.

IGN TIMING

BTDC

• Indicates the ignition timing computed by ECM ac-

cording to the input signals.

• When the engine is stopped, 

a certain value is indicated.

COMBUSTION

—

• These items are displayed but are not applicable to 

this model.

CAL/LD VALUE

%

• “Calculated load value” indicates the value of the 

current air flow divided by peak air flow.

MASS AIRFLOW

g/s

• Indicates the mass air flow computed by ECM ac-

cording to the signal voltage of the mass air flow 
sensor.

PURG VOL C/V

%

• Indicates the EVAP canister purge volume control 

solenoid valve control value computed by the ECM 
according to the input signals.

• The opening becomes larger as the value increas-

es.

INT/V SOL (B1)

%

• The control value of the intake valve timing control 

solenoid valve (determined by ECM according to 
the input signals) is indicated.

• The advance angle becomes larger as the value 

increases.

INT/V SOL (B2)

AIR COND RLY

ON/OFF

• The air conditioner relay control condition (deter-

mined by ECM according to the input signals) is in-
dicated.

VENT CONT/V

ON/OFF

• The control condition of the EVAP canister vent 

control valve (determined by ECM according to the 
input signals) is indicated.
ON: Closed
OFF: Open

THRTL RELAY

ON/OFF

• Indicates the throttle control motor relay control 

condition determined by the ECM according to the 
input signals.

A/F S1 HTR (B1)

%

• Air fuel ratio (A/F) sensor 1 heater control value 

computed by ECM according to the input signals.

• The current flow to the heater becomes larger as 

the value increases.

A/F S1 HTR (B2)

HO2S2 HTR (B1)

ON/OFF

• Indicates [ON/OFF] condition of heated oxygen 

sensor 2 heater determined by ECM according to 
the input signals.

HO2S2 HTR (B2)

ALT DUTY SIG

ON/OFF

• The control condition of the power generation volt-

age variable control (determined by ECM accord-
ing to the input signals) is indicated.
ON: Power generation voltage variable control is 
active.
OFF: Power generation voltage variable control is 
inactive.

I/P PULLY SPD

rpm

• Indicates the engine speed computed from the in-

put speed sensor signal.

Monitored item

Unit

Description

Remarks

EC-68

< SYSTEM DESCRIPTION >

[VK56VD]

DIAGNOSIS SYSTEM (ECM)

VEHICLE SPEED

km/h or mph

• The vehicle speed computed from the vehicle 

speed signal sent from TCM is displayed.

IDL A/V LEARN

YET/CMPLT

• Displays the condition of Idle Air Volume Learning

YET: Idle air volume learning has not been per-
formed yet.
CMPLT: Idle air volume learning has already been 
performed successfully.

TRVL AFTER MIL

km or mile

• Distance traveled while MIL is activated.

SNOW MODE SW

ON/OFF

• Indicates [ON/OFF] condition from the snow mode 

switch signal.

ENG OIL TEMP

°

C or 

°

F

• The engine oil temperature (determined by the sig-

nal voltage of the engine oil temperature sensor) is 
displayed.

MAIN SW

ON/OFF

• Indicates [ON/OFF] condition from MAIN switch 

signal.

CANCEL SW

ON/OFF

• Indicates [ON/OFF] condition from CANCEL 

switch signal.

RESUME/ACC SW

ON/OFF

• Indicates [ON/OFF] condition from RESUME/AC-

CELERATE switch signal.

SET SW

ON/OFF

• Indicates [ON/OFF] condition from SET/COAST 

switch signal.

BRAKE SW1

ON/OFF

• Indicates [ON/OFF] condition from ASCD brake 

switch signal.

BRAKE SW2

ON/OFF

• Indicates [ON/OFF] condition of stop lamp switch 

signal.

DIST SW

ON/OFF

• Indicates [ON/OFF] condition from DISTANCE 

switch signal.

CRUISE LAMP

ON/OFF

• Indicates [ON/OFF] condition of CRUISE indicator 

determined by the ECM according to the input sig-
nals.

AC EVA TEMP

°

C or 

°

F

• Indicates A/C evaporator temperature sent from A/

C auto amp.

AC EVA TARGET

°

C or 

°

F

• Indicates target A/C evaporator temperature sent 

from A/C auto amp.

FAN DUTY

%

• Indicates a command value for cooling fan. The 

value is calculated by ECM based on input signals.

ALT DUTY

%

• Indicates the duty ratio of the power generation 

command value. The ratio is calculated by ECM 
based on the battery current sensor signal.

BAT CUR SEN

mV

• The signal voltage of battery current sensor is dis-

played.

A/F ADJ-B1

—

• Indicates the correction of a factor stored in ECM. 

The factor is calculated from the difference be-
tween the target air-fuel ratio stored in ECM and 
the air-fuel ratio calculated from A/F sensor 1 sig-
nal.

A/F ADJ-B2

P/N POSI SW

ON/OFF

• Indicates [ON/OFF] condition from the park/neutral 

position (PNP) signal.

INT/A TEMP SE

°

C or 

°

F

• The intake air temperature (determined by the sig-

nal voltage of the intake air temperature sensor) is 
indicated.

AC PRESS SEN

V

• The signal voltage from the refrigerant pressure 

sensor is displayed.

FUEL PRES SEN

MPa

• Indicates the fuel rail pressure computed by ECM 

according to the input signals

Monitored item

Unit

Description

Remarks

DIAGNOSIS SYSTEM (ECM)

EC-69

< SYSTEM DESCRIPTION >

[VK56VD]

C

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F

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FUEL INJ B1

msec

• ECM-calculated injection pulse width of the fuel in-

jector on the Bank 1 side.

FUEL INJ B2

msec

• ECM-calculated injection pulse width of the fuel in-

jector on the Bank 2 side.

INT/V TIM (B1)

°

CA

• Indicates [

°

CA] of intake camshaft advance angle. 

INT/V TIM (B2)

MAP SENSOR

V

• The signal voltage from the manifold absolute 

pressure (MAP) sensor is displayed.

EVAP LEAK DIAG

YET/CMPLT

• Indicates the condition of EVAP leak diagnosis.

YET: EVAP leak diagnosis has not been performed 
yet.
CMPLT: EVAP leak diagnosis has been performed 
successfully.

EVAP DIAG READY

ON/OFF

• Indicates the ready condition of EVAP leak diagno-

sis.
ON: Diagnosis has been ready condition.
OFF: Diagnosis has not been ready condition.

VVEL LEARN

YET/DONE

• Display the condition of VVEL learning

YET: VVEL learning has not been performed yet.
DONE: VVEL learning has already been per-
formed successfully.

VVEL SEN LEARN-B1

V

• Indicates the VVEL learning value.

VVEL SEN LEARN-B2

VVEL POSITION SEN-B1

V

• The VVEL control shaft position sensor signal volt-

age is displayed.

VVEL POSITION SEN-B2

VVEL TIM-B1

deg

• Indicates [deg] of VVEL control shaft angle. 

VVEL TIM-B2

FPCM

HI/MID/LOW/

OFF

• The control condition of the fuel pump control mod-

ule (FPCM) (determined by ECM according to the 
input signals) is indicated.

BAT TEMP SEN

V

• The signal voltage from the battery temperature 

sensor is displayed.

COOLING FAN SPD

rpm

• Displays a cooling fan speed from a signal of elec-

trically-controlled cooling fan coupling.

THRTL STK CNT B1*

—

—

HO2 S2 DIAG2(B1)*

INCMP/CM-

PLT

• Indicates DTC P0139 self-diagnosis (slow re-

sponse) condition.
INCMP: Self-diagnosis is incomplete.
CMPLT: Self-diagnosis is complete.

HO2 S2 DIAG2(B2)*

INCMP/CM-

PLT

• Indicates DTC P0159 self-diagnosis (slow re-

sponse) condition.
INCMP: Self-diagnosis is incomplete.
CMPLT: Self-diagnosis is complete.

FUEL INJ TIMG

deg

• Indicates the fuel injection timing computed by 

ECM according to the input signals.

H/P FUEL PUMP DEG

deg

• Displays ECM-calculated fuel discharge position 

of the high pressure fuel pump.

FUEL PRES SEN V

mV

• The signal voltage of FRP sensor is displayed.

L/FUEL PRES SEN

MPa

• Displays a pressure value calculated from a low 

fuel pressure sensor voltage.

L/FUEL PRES SEN V

mV

• The signal voltage of low fuel pressure sensor is 

displayed.

Monitored item

Unit

Description

Remarks