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EC-106Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
5. Touch “ENGINE”.
If “ENGINE” is not indicated, go to GI-39, "
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
TARGET IDLE RPM ADJ*
IDLE CONDITION When setting target idle speed
TARGET IGN TIM ADJ*
IDLE CONDITION When adjusting target ignition tim-
ing
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TROUBLE DIAGNOSIS
EC-107
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*: 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-8, "INDEX FOR DTC" .)
Freeze Frame Data and 1st Trip Freeze Frame Data
*1: The items are the same as those of 1st trip freeze frame data.
DATA MONITOR MODE
Monitored Item
×: Applicable Freeze frame data
item*
1Description
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.
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.
Monitored item
[Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription 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 injec-
tion pulse width programmed into ECM, prior
to any learned on board correction.
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![INFINITI QX56 2004 Factory Service Manual EC-108Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
A/F ALPHA-B1 [%]×
The mean value of the air-fuel ratio feedback
correction factor per cycle is indicated.
When the engine is stopped, a c INFINITI QX56 2004 Factory Service Manual EC-108Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
A/F ALPHA-B1 [%]×
The mean value of the air-fuel ratio feedback
correction factor per cycle is indicated.
When the engine is stopped, a c](/manual-img/42/57034/w960_57034-1298.png)
EC-108Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
A/F ALPHA-B1 [%]×
The mean value of the air-fuel ratio feedback
correction 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. A/F ALPHA-B2 [%]×
COOLAN TEMP/S
[°C] or [°F]××
The engine coolant temperature (determined
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 sen-
sor 2 is displayed.
HO2S2 (B2) [V]×
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)
[RICH/LEAN]×
VHCL SPEED SE
[km/h] or [mph]××
The vehicle speed computed from the vehicle
speed signal sent from combination 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 [V]×Accelerator pedal position sensor 2
signal is converted by ECM internally.
Thus, it differs from ECM terminal volt-
age signal.
THRTL SEN 1 [V]××
The throttle position sensor signal voltage is
displayed.
THRTL SEN 2 [V]×Throttle position sensor 2 signal is
converted by ECM internally. Thus, it
differs from ECM terminal voltage sig-
nal.
FUEL T/TEMP SE
[°C] or [°F]×
The fuel temperature (determined by the sig-
nal voltage of the fuel tank temperature sen-
sor) 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 system
pressure sensor is displayed.
FUEL LEVEL SE
[V]×
The signal voltage of the fuel level sensor is
displayed.
START SIGNAL
[ON/OFF]××
Indicates start signal status [ON/OFF] com-
puted by the ECM according to the signals of
engine speed and battery voltage.After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS
[ON/OFF]××
Indicates idle position [ON/OFF] computed by
ECM according to the accelerator pedal posi-
tion sensor signal.
AIR COND SIG
[ON/OFF]××
Indicates [ON/OFF] condition of the air condi-
tioner switch as determined by the air condi-
tioner signal. Monitored item
[Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription Remarks
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![INFINITI QX56 2004 Factory Service Manual TROUBLE DIAGNOSIS
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[ON/OFF]××Indicates [ON/OFF] condition from the park/
neutral position (PNP) switch signal.
PW/ST SIGNAL INFINITI QX56 2004 Factory Service Manual TROUBLE DIAGNOSIS
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[ON/OFF]××Indicates [ON/OFF] condition from the park/
neutral position (PNP) switch signal.
PW/ST SIGNAL](/manual-img/42/57034/w960_57034-1299.png)
TROUBLE DIAGNOSIS
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[ON/OFF]××Indicates [ON/OFF] condition from the park/
neutral position (PNP) switch signal.
PW/ST SIGNAL
[ON/OFF]××
[ON/OFF] condition of the power steering sys-
tem (determined by the signal voltage of the
power steering pressure sensor signal) is indi-
cated.
LOAD SIGNAL
[ON/OFF]××
Indicates [ON/OFF] condition from the electri-
cal 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 ignition
switch signal.
HEATER FAN SW
[ON/OFF]
Indicates [ON/OFF] condition from the 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 volume
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 condition
(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 sig-
nals.
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 con-
trol condition determined by the ECM accord-
ing to the input signals.
COOLING FAN
[HI/OFF]
The control condition of the cooling fan (deter-
mined by ECM according to the input signals)
is indicated.
ON: Operating
OFF: Stop Monitored item
[Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription Remarks
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![INFINITI QX56 2004 Factory Service Manual EC-110Revision: August 2007
TROUBLE DIAGNOSIS
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HO2S2 HTR (B1)
[ON/OFF]Indicates [ON/OFF] condition of heated oxy-
gen sensor 2 heater determined by ECM
according to the input signals. HO2S INFINITI QX56 2004 Factory Service Manual EC-110Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
HO2S2 HTR (B1)
[ON/OFF]Indicates [ON/OFF] condition of heated oxy-
gen sensor 2 heater determined by ECM
according to the input signals. HO2S](/manual-img/42/57034/w960_57034-1300.png)
EC-110Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
HO2S2 HTR (B1)
[ON/OFF]Indicates [ON/OFF] condition of heated oxy-
gen 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 signal.
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 learn-
ing
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)
[%]
Indicates A/F sensor 1 heater control value
computed by the ECM according to the input
signals.
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 pres-
sure sensor is displayed.
VHCL SPEED SE
[km/h] or [mph]
The vehicle speed computed from the vehicle
speed signal sent from TCM is displayed.
SET VHCL SPD
[km/h] or [mph]
The preset vehicle speed is displayed.
MAIN SW
[ON/OFF]
Indicates [ON/OFF] condition from ON/
OFF(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 ACCEL/
RESUME switch signal.
SET SW
[ON/OFF]
Indicates [ON/OFF] condition from COAST/
SET switch signal.
DIST SW
[ON/OFF]
Indicates [ON/OFF] condition from DISTANCE
switch signal.
BRAKE SW1 SW
[ON/OFF]
Indicates [ON/OFF] condition from ASCD
brake switch signal.
BRAKE SW2 SW
[ON/OFF]
Indicates [ON/OFF] condition of stop lamp
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 excessively
high compared with the ASCD set speed, and
ASCD operation is cut off.
LOW SPEED CUT
[NON/CUT]
Indicates the vehicle cruise condition.
NON: Vehicle speed is maintained at the
ASCD set speed.
CUT: Vehicle speed decreased to excessively
low compared with the ASCD set speed, and
ASCD operation is cut off. Monitored item
[Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription Remarks
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NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
DATA MONITOR (SPEC) MODE
Monitored Item
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.AT O D M O N I T O R
[ON/OFF]
Indicates [ON/OFF] condition of A/T O/D
according to the input signal from TCM.
AT OD CANCEL
[ON/OFF]
Indicates [ON/OFF] condition of A/T O/D can-
cel signal from TCM.
CRUISE LAMP
[ON/OFF]
Indicates [ON/OFF] condition of CRUISE lamp
determined by the ECM according to the input
signals.
SET LAMP
[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-LOWMonitored item
[Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription Remarks
Monitored item [Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription Remarks
ENG SPEED [rpm]××
Indicates the engine speed computed
from the signal of the crankshaft position
sensor (POS).
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.
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.
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EC-112Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
ACTIVE TEST MODE
Test Item
*: Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-55, "SYSTEM READINESS TEST (SRT) CODE" .
SRT Work Support Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
TEST ITEM CONDITION JUDGEMENT CHECK 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
Shift lever 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 ON 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
FUEL/T TEMP
SEN
Change the fuel tank temperature using CONSULT-II.
VENT CON-
TROL/V
Ignition switch: ON (Engine
stopped)
Turn solenoid valve ON and OFF
with the CONSULT-II and listen
to operating sound.Solenoid valve makes an operating
sound.Harness and connectors
Solenoid valve
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TROUBLE DIAGNOSIS
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DTC Work Support Mode
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.Test mode Test item Condition Reference page
EVAPORATIVE SYSTEMPURGE FLOW P0441
Refer to corresponding
trouble diagnosis for DTC.EC-271
EVAP SML LEAK P0442/P1442*EC-276
EVAP V/S SML LEAK P0456/P1456*EC-324
PURG VOL CN/V P1444EC-496
A/F SEN1A/F SEN1 (B1) P1276EC-463A/F SEN1 (B2) P1286EC-463
A/F SEN1 (B1) P1278/P1279EC-472, EC-484
A/F SEN1 (B2) P1288/1289EC-472, EC-484
H02S2HO2S2 (B1) P0139EC-196
HO2S2 (B1) P1146EC-383
HO2S2 (B1) P1147EC-395
HO2S2 (B2) P0159EC-196
HO2S2 (B2) P1166EC-383
HO2S2 (B2) P1167EC-395