2006 INFINITI QX56 engine

EC-116Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
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-II screen in freeze frame data
mode only if a 1st trip DTC or DTC is detected. For details, refer to EC-118, "
Freeze Frame Data and 1st Trip Freeze Frame Data" .
INSPECTION PROCEDURE
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carry out CAN communication.
1. Turn ignition switch OFF.
2. Connect CONSULT-II and CONSULT-II CONVERTER to data
link connector, which is located under LH dash panel near the
hood opener handle.
3. Turn ignition switch ON.
4. Touch “START (NISSAN BASED VHCL) ”.
ENGINE CONTROL COMPONENT PARTS
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 ××××
Heated oxygen sensor 2 heater ××××
EVAP canister vent control valve ×× ×××
Calculated load value ×××
Item
DIAGNOSTIC TEST MODE
WORK SUP-
PORT SELF-DIAGNOSTIC
RESULTS DATA
MONI- TOR DATA
MONI-
TOR
(SPEC) ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*1 FREEZE
FRAME
DATA*2 SRT
STATUS DTC
WORK
SUP-
PORT
BBIA0369E
BCIA0029E

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Revision: November 2009 2006 QX56
5. Touch “ENGINE”.
If “ENGINE ” is not indicated, go to GI-40, "
CONSULT-II Data
Link Connector (DLC) Circuit" .
6. Perform each diagnostic test mode according to each service procedure.
For further information, see the CONSULT-II Operation Manual.
WORK SUPPORT MODE
Work Item
BCIA0030E
BCIA0031E
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
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-
II WILL DISCONTINUE IT AND DISPLAY APPROPRI-
ATE INSTRUCTION.
NOTE:
WHEN STARTING ENGINE, CONSULT-II MAY DISPLAY
“BATTERY VOLTAGE IS LOW. CHARGE BATTERY”,
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

EC-118Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
*: 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-49, "EMISSION-RELATED DIAGNOSTIC INFORMA-
TION ITEMS" .
Freeze Frame Data and 1st Trip Freeze Frame Data
*: The item is the same as that of 1st trip freeze frame data.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-8, "
INDEX FOR DTC" .)
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
schedule.
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.
INT/A TEMP SE
[ °C] or [°F]

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

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Revision: November 2009 2006 QX56
DATA MONITOR MODE
Monitored Item
×: Applicable
Monitored item [Unit] ECM
INPUT
SIGNALS 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
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.
B/FUEL SCHDL
[msec] ×

Base fuel schedule indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.
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.

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
displayed.
When the engine coolant temperature
sensor is open or short-circuited, ECM
enters fail-safe mode. The engine
coolant 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
after 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]
×
THRTL SEN 1 [V] ××

The throttle position sensor signal volt-
age is displayed.
THRTL SEN 2 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal.
THRTL SEN 2 [V]
×
FUEL T/TMP SE
[ °C] or [°F] ×

The fuel temperature (determined by the
signal voltage of the fuel tank tempera-
ture sensor) is displayed.
INT/A TEMP SE
[ °C] or [°F] ××

The intake air temperature (determined
by the signal voltage of the intake air
temperature sensor) is indicated.
EVAP SYS PRES
[V] ×

The signal voltage of EVAP control sys-
tem pressure sensor is displayed.

EC-120Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
FUEL LEVEL SE
[V]×
The signal voltage of the fuel level sen-
sor is displayed.
START SIGNAL
[ON/OFF] ××

Indicates start signal status [ON/OFF]
computed by the ECM according to the
signals of engine speed and battery volt-
age.

After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS
[ON/OFF] ××

Indicates idle position [ON/OFF] com-
puted by ECM according to the acceler-
ator 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.
P/N POSI SW
[ON/OFF] ××

Indicates [ON/OFF] condition from the
park/neutral position (PNP) switch sig-
nal.
PW/ST SIGNAL
[ON/OFF] ××

[ON/OFF] condition of the power steer-
ing system (determined by the signal
voltage of the power steering pressure
sensor signal) is indicated.
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 lighting switch are OFF.
IGNITION SW
[ON/OFF] ×

Indicates [ON/OFF] condition from igni-
tion switch signal.
HEATER FAN SW
[ON/OFF] ×

Indicates [ON/OFF] condition from
heater fan switch signal.
BRAKE SW
[ON/OFF] ×

Indicates [ON/OFF] condition from the
stop lamp switch signal.
INJ PULSE-B1
[msec] ×

Indicates the actual fuel injection pulse
width compensated by ECM according
to the input signals.
When the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2
[msec]
IGN TIMING
[BTDC] ×

Indicates the ignition timing computed
by ECM according to the input signals.
When the engine is stopped, a certain
value is indicated.
CAL/LD VALUE [%]

“ Calculated load value ” indicates the
value of the current air flow divided by
peak air flow.
MASS AIRFLOW
[g ·m/s]

Indicates the mass air flow computed by
ECM according to the signal voltage of
the mass air flow sensor.
PURG VOL C/V [%]

Indicates the EVAP canister purge vol-
ume control solenoid valve control value
computed by the ECM according to the
input signals.

The opening becomes larger as the
value increases.
AIR COND RLY
[ON/OFF] ×

The air conditioner relay control condi-
tion (determined by ECM according to
the input signals) is indicated.
FUEL PUMP RLY
[ON/OFF] ×

Indicates the fuel pump relay control
condition determined by ECM according
to the input signals.
Monitored item
[Unit] ECM
INPUT
SIGNALS MAIN
SIGNALS Description Remarks

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Revision: November 2009 2006 QX56VENT CONT/V
[ON/OFF]

The control condition of the EVAP canis-
ter 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.
COOLING FAN
[HI/OFF] ×

The control condition of the cooling fan
(determined by ECM according to the
input signals) is indicated.
HI: High speed operation
OFF: Stop
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)
[ON/OFF]
I/P PULLY SPD
[rpm]

Indicates the engine speed computed
from the turbine revolution sensor sig-
nal.
VEHICLE SPEED
[km/h] or [MPH]

Indicates the vehicle speed computed
from the revolution sensor signal.
IDL A/V LEARN
[YET/CMPLT]

Display the condition of idle air volume
learning
YET: Idle Air Volume Learning has not
been performed yet.
CMPLT: Idle Air Volume Learning has
already been performed successfully.
TRVL AFTER MIL
[km] or [mile]

Distance traveled while MIL is activated.
A/F S1 HTR (B1)
[%]

A/F sensor 1 heater control value com-
puted by ECM according to the input sig-
nals.

The current flow to the heater becomes
larger as the value increases.
A/F S1 HTR (B2)
[%]
AC PRESS SEN [V]

The signal voltage from the refrigerant
pressure sensor is displayed.
VHCL SPEED SE
[km/h] or [mph]

The vehicle speed computed from the
vehicle speed signal sent from combina-
tion meter is displayed.
SET VHCL SPD*
1
[km/h] or [mph]
The preset vehicle speed is displayed.
MAIN SW
[ON/OFF]

Indicates [ON/OFF] condition from MAIN
switch signal.
CANCEL SW
[ON/OFF]

Indicates [ON/OFF] condition from CAN-
CEL switch signal.
RESUME/ACC SW
[ON/OFF]

Indicates [ON/OFF] condition from
RESUME/ACCELERATE 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.
Monitored item
[Unit] ECM
INPUT
SIGNALS MAIN
SIGNALS Description Remarks

EC-122Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
*1: Models with ASCD
*2: Models with ICC
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
DATA MONITOR (SPEC) MODE
Monitored Item
BRAKE SW2
[ON/OFF]
Indicates [ON/OFF] condition of stop
lamp switch signal.
DIST SW*
2
[ON/OFF]

Indicates [ON/OFF] condition from DIS-
TANCE switch signal.
VHCL SPD CUT
[NON/CUT]

Indicates the vehicle cruise condition.
NON: Vehicle speed is maintained at the
ASCD set speed.
CUT: Vehicle speed increased to exces-
sively high compared with the ASCD set
speed, and ASCD operation is cut off.
LO SPEED CUT*
1
[NON/CUT]

Indicates the vehicle cruise condition.
NON: Vehicle speed is maintained at the
ASCD set speed.
CUT: Vehicle speed decreased to exces-
sively low compared with the ASCD set
speed, and ASCD operation is cut off.
AT OD MONITOR*
1
[ON/OFF]

Indicates [ON/OFF] condition of A/T O/D
according to the input signal from the
TCM.
AT OD CANCEL*
1
[ON/OFF]

Indicates [ON/OFF] condition of A/T O/D
cancel signal sent from the TCM.
CRUISE LAMP
[ON/OFF]

Indicates [ON/OFF] condition of
CRUISE lamp determined by the ECM
according to the input signals.
SET LAMP*
1
[ON/OFF]

Indicates [ON/OFF] condition of SET
lamp determined by the ECM according
to the input signals.
Voltage [V]

Voltage, frequency, duty cycle or pulse
width measured by the probe.

Only # is displayed if item is unable to
be measured.

Figures with #s are temporary ones.
They are the same figures as an actual
piece of data which was just previously
measured.
Frequency [msec],
[Hz] or [%]
DUTY-HI
DUTY-LOW
PLS WIDTH-HI
PLS WIDTH-LOW Monitored item
[Unit] ECM
INPUT
SIGNALS MAIN
SIGNALS Description Remarks
Monitored item
[Unit] ECM
INPUT
SIGNALS 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).
MAS A/F SE-B1 [V] ××

The signal voltage of the mass air flow
sensor specification is displayed.
When engine is running specification
range is indicated.

TROUBLE DIAGNOSISEC-123
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Revision: November 2009 2006 QX56
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
B/FUEL SCHDL
[msec]×

Base fuel schedule indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.

When engine is running specification
range is indicated.
A/F ALPHA-B1 [%]
A/F ALPHA-B2 [%] ×

The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.
When engine is running specification
range is indicated.

This data also includes the data for
the air-fuel ratio learning control.
Monitored item
[Unit] ECM
INPUT
SIGNALS MAIN
SIGNALS Description
Remarks
TEST ITEMCONDITION JUDGEMENTCHECK ITEM (REMEDY)
FUEL INJEC-
TION

Engine: Return to the original
trouble condition

Change the amount of fuel injec-
tion using CONSULT-II. If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Fuel injector

Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING

Engine: Return to the original
trouble condition

Timing light: Set

Retard the ignition timing using
CONSULT-II. If trouble symptom disappears, see
CHECK ITEM.

Perform Idle Air Volume Learning.
POWER BAL-
ANCE

Engine: After warming up, idle
the engine.

A/C switch: OFF

Selector lever: P or N

Cut off each injector signal one at
a time using CONSULT-II. Engine runs rough or dies.

Harness and connectors

Compression

Fuel injector

Power transistor

Spark plug

Ignition coil
COOLING FAN*

Ignition switch: ON

Turn the cooling fan HI and OFF
using CONSULT-II. Cooling fan moves and stops.

Harness and connectors

Cooling fan motor

IPDM E/R
ENG COOLANT
TEMP

Engine: Return to the original
trouble condition

Change the engine coolant tem-
perature using CONSULT-II. If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Engine coolant temperature sen-
sor

Fuel injector
FUEL PUMP
RELAY

Ignition switch: ON
(Engine stopped)

Turn the fuel pump relay ON and
OFF using CONSULT-II and lis-
ten to operating sound. Fuel pump relay makes the operat-
ing sound.
Harness and connectors

Fuel pump relay
PURG VOL
CONT/V

Engine: After warming up, run
engine at 1,500 rpm.

Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II. Engine speed changes according to
the opening percent.
Harness and connectors

Solenoid valve