2011 INFINITI QX56 engine

EC-58
< SYSTEM DESCRIPTION >[VK56VD]
DIAGNOSIS SYSTEM (ECM)
DIAGNOSIS DESCRIPTION : Driving Pattern
INFOID:0000000006217725
DRIVING PATTERN A
 The A counter will be cleared when the malfunction is detected regardless of (1) - (4).
 The A counter will be counted up when (1) - (4) are satisfied without the same malfunction.
 The DTC will not be displayed after the A counter reaches 40.
DRIVING PATTERN B
Driving pattern B means operating vehicle operation as per the following:
All components and systems should be monito red at least once by the OBD system.
 The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.
 The B counter will be counted up when driving patt ern B is satisfied without any malfunctions.
 The MIL will turn OFF when the B counter reaches 3.
DRIVING PATTERN C
Driving pattern C means operating vehicle as per the following:
The following conditions should be satisfied at the same time:
Engine speed: (Engine speed in the freeze frame data) ±375 rpm
Calculated load value: (Calculated load value in the freeze frame data) x (1 ±0.1) [%]
Engine coolant temperature (T) condition:
 When the freeze frame data shows lower than 70 °C (158 °F), T should be lower than 70 °C (158 °F).
 When the freeze frame data shows higher than or equal to 70 °C (158 °F), T should be higher than or equal to
70 °C (158 °F).
 The C counter will be cleared when the malfunction is detected regardless of vehicle conditions above.
 The C counter will be counted up when vehicle conditions above are satisfied without the same malfunction.
 The DTC will not be displayed after C counter reaches 80.
 The 1st trip DTC will be cleared when C counter is c ounted once without the same malfunction after DTC is
stored in ECM.
DIAGNOSIS DESCRIPTION : System Readiness Test (SRT) CodeINFOID:0000000006217726
System Readiness Test (SRT) code is spec ified in Service $01 of SAE J1979/ISO 15031-5.
As part of an enhanced emissions test for Inspection & Ma intenance (I/M), certain states require the status of
SRT be used to indicate whether the ECM has completed self-diagnosis of major emission s\
ystems and com-
ponents. Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspec tion due to one or more SRT items indicating “INCMP”, use
the information in this Service Manual to set the SRT to “CMPLT”.
In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT
status will indicate “CMPLT” for each application system . Once set as “CMPLT”, the SRT status remains
“CMPLT” until the self-diagnosis memory is erased.
Occasionally, certain portions of the self-diagnostic test may not be completed as a result of the customer's
normal driving pattern; the SRT will indicate “INCMP” for these items.
NOTE:
JMBIA1920GB
Revision: 2010 May2011 QX56

EC-60
< SYSTEM DESCRIPTION >[VK56VD]
DIAGNOSIS SYSTEM (ECM)
DIAGNOSIS DESCRIPTION : Malf unction Indicator Lamp (MIL)
INFOID:0000000006217727
DESCRIPTION
The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON with-
out the engine running. This is a bulb check.
If the MIL does not light up, refer to EC-515, "
Component Func-
tion Check".
2. When the engine is started, the MIL should go off. If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction.
On Board Diagn osis FunctionINFOID:0000000006217728
ON BOARD DIAGNOSIS ITEM
The on board diagnostic system has the following functions.
BLUB CHECK MODE
Description
This function allows damage inspection in the MIL bulb (blown, open circuit, etc.).
Operation Procedure
1. Turn ignition switch ON.
2. The MIL on the instrument panel should stay ON.
If it remains OFF, check MIL circuit. Refer to EC-515, "
Diagnosis Procedure".
SRT STATUS MODE
Description
This function allows to read if ECM has completed t he self-diagnoses of major emission control systems and
components. For SRT, refer to EC-58, "
DIAGNOSIS DESCRIPTION : Syst em Readiness Test (SRT) Code".
Operation Procedure
1. Turn ignition switch ON and wait 20 seconds.
2. SRT status is indicated as shown blow.
 ECM continues to illuminate MIL if all SRT codes are set.
SEF217U
Diagnostic test mode Function
Bulb check MIL can be checked.
SRT status ECM can read if SRT codes are set.
Malfunction warning If ECM detects a malfunction, it illuminates or blinks MIL to inform the driver that a malfunction has been detected.
Self-diagnostic results DTCs or 1st trip DTCs stored in ECM can be read.
Accelerator pedal released po-
sition learning ECM can learn the accelerator pedal released position. Refer to
EC-146, "
Description".
Throttle valve closed position
learning ECM can learn the throttle valve closed position. Refer to
EC-147, "
Description".
Idle air volume learning ECM can learn the idle air volume. Refer to EC-148, "
Description".
VVEL control sh aft position
sensor adjustment The initial position of the VVEL control shaft position sensor can be adjusted. Refer to
EC-150, "
De-
scription".
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (ECM)EC-61
< SYSTEM DESCRIPTION > [VK56VD]
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 ECM blinks MIL for about 10 seconds if all SRT codes are not set.
MALFUNCTION WARNING MODE
Description
In this function ECM turns on or blinks MIL when it det
ects a malfunction in the emission control system com-
ponents and/or the powertrain control components (which affe ct vehicle emissions) to inform the driver that a
malfunction has been detected.
Operation Procedure
1. Turn ignition switch ON.
2. Check that MIL illuminates. If it remains OFF, check MIL circuit. Refer to EC-515, "
Diagnosis Procedure".
3. Start engine and let it idle.  For two trip detection logic diagnoses, ECM turns on MIL when it detects the same malfunction twice in
the two consecutive driving cycles.
 For 1st trip detection logic diagnoses, ECM turns on MIL when it detects a malfunction in one driving cycle.
 ECM blinks MIL when it detects a malfunction t hat may damage the three way catalyst (misfire).
SELF-DIAGNOSTIC RESULTS MODE
Description
This function allows to indicate DTCs or 1st trip DTCs stored in ECM according to the number of times MIL is
blinking.
How to Set Self-diagnostic Results Mode
NOTE:
 It is better to count the time accurately with a clock.
 It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit has a mal-
function.
 After ignition switch is turned off, ECM is a lways released from the “Self-diagnostic results” mode.
1. Confirm that accelerator pedal is fully releas ed, turn ignition switch ON and wait 3 seconds.
2. Repeat the following procedure quickly five times within 5 seconds.  Fully depress the accelerator pedal.
 Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it depressed for approx. 10 seconds until the
MIL starts blinking.
NOTE:
Do not release the accelerator pedal for 10 seconds if MIL starts blinking during this period. This blinking
is displaying SRT status and is continued for another 10 seconds.
4. Fully release the accelerator pedal. ECM has entered to Self-diagnostic results mode.
JMBIA1515GB
Revision: 2010 May2011 QX56

EC-64
< SYSTEM DESCRIPTION >[VK56VD]
DIAGNOSIS SYSTEM (ECM)
*: 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-98, "DTC Index".
How to Read DTC and 1st Trip DTC
DTCs and 1st trip DTCs related to the malfunction are displayed in “Self-diag results”.
 When ECM detects a 1st trip DTC, “1t” is displayed for “TIME”.
 When ECM has detected a current DTC, “0” is displayed for “TIME”.
 If “TIME” is neither “0” nor “1t”, the DTC occurred in the past and ECM shows the number of times the vehi-
cle has been driven since the last detection of the DTC.
How to Erase DTC and 1st Trip DTC
NOTE:
 If the ignition switch stays ON after repair work, be su re to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
 If the DTC is not for A/T related items (see EC-98, "
DTC Index"), skip step 1.
1. Erase DTC in TCM. Refer to TM-60, "
Diagnosis Description".
2. Select “ENGINE” with CONSULT-III.
3. Select “SELF-DIAG RESULTS”.
4. Touch “ERASE”. (DTC in ECM will be erased.)
WORK ITEM CONDITION USAGE
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
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 WHEN USING A CHARGED BATTERY. When detecting EVAP vapor leak
in the EVAP system
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
SELF-LEARNING CONT  THE COEFFICIENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT. When clearing mixture ratio self-
learning value
TARGET IDLE RPM ADJ*  IDLE CONDITION When setting target idle speed
VIN REGISTRATION  IN THIS MODE, VIN IS REGISTERED IN ECM. When registering VIN in ECM
TARGET IGN TIM ADJ*  IDLE CONDITION When adjusting target ignition tim-
ing
CLSD THL POS LEARN  IGNITION ON AND ENGINE STOPPED. When learning the throttle valve
closed position
VVEL POS SEN ADJ PREP  USE THIS ITEM ONLY WHEN REPLACING VVEL ACTU-
ATOR SUB ASSEMBLY.
 IGNITION ON AND ENGINE STOPPED. When adjusting VVEL control
shaft position sensor
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (ECM)EC-65
< SYSTEM DESCRIPTION > [VK56VD]
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Freeze Frame Data and 1st Trip Freeze Frame Data
*: The items are the same as those of 1st trip freeze frame data.
DATA MONITOR MODE
Monitored Item
×
: Applicable
Freeze frame data
item* Description
DIAG TROUBLE
CODE
[PXXXX]  The engine control compon
ent part/control system has a trouble code the is displayed as PXXXX. (Refer to
EC-98, "
DTC Index".)
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.
INT MANI PRES [kPa]  These items are displayed but are not applicable to this model.
ABSOL TH·P/S [%]  The throttle valve opening angle 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.
INT/A TEMP SE [ °C]
or [ °F]  The intake air temperature at the moment a malfunction is detected is displayed.
FUEL SYS-B1  “Fuel injection system status” at the moment a malfunction is detected is displayed.  One of the following mode 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
COMBUST CONDI-
TION
 These items are displayed but are not applicable to this model.
Monitored item Unit Description Remarks
ENG SPEED rpm  Indicates the engine speed computed from the sig-
nal of the crankshaft position sensor and camshaft
position sensor.  Accuracy becomes poor if
engine speed drops below
the idle rpm.
 If the signal is interrupted while the engine 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 indicat-
ed in “SPEC”.
B/FUEL SCHDL ms  “Base fuel schedule” indicates the fuel injection
pulse width programmed into ECM, prior to any
learned on board correction.  When engine is running,
specification range is indicat-
ed in “SPEC”.
Revision: 2010 May2011 QX56

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
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (ECM)EC-67
< SYSTEM DESCRIPTION > [VK56VD]
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OLOAD 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 co
ntrol 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
Revision: 2010 May2011 QX56

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
Revision: 2010 May2011 QX56