TROUBLE DIAGNOSISEC-95
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Revision: November 2009 2006 QX56
1 - 6: The numbers refer to the order of inspection.Exhaust Exhaust manifold/Tube/Muffler/
Gasket 55555 55 5 EM-21
,
EX-
3Three way catalyst
Lubrica-
tion Oil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5EM-24
,
LU-
13 , LU-10 ,
LU-11
Oil level (Low)/Filthy oil LU-7
Cooling Radiator/Hose/Radiator filler cap
55555 55 45 CO-14
Thermostat
5CO-21
Water pump CO-19
Water galleryCO-8
Cooling fan5CO-17
Coolant level (Low)/Contami-
nated coolant 5
CO-10
IVIS (INFINITI Vehicle Immobilizer System —
NATS) 11
BL-137
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
EC-110Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
66 RSensor ground
(Throttle position sensor) [Engine is running]Warm-up condition
Idle speed
Approximately 0V
67 B Sensor ground [Engine is running]
Warm-up condition
Idle speedApproximately 0V
68 W/L Sensor power supply
(PSP sensor) [Ignition switch: ON]
Approximately 5V
69 W Throttle position sensor 2 [Ignition switch: ON]
Engine: Stopped
Selector lever: D
Accelerator pedal: Fully released
Less than 4.75V
[Ignition switch: ON]
Engine: Stopped
Selector lever: D
Accelerator pedal: Fully depressed More than 0.36V
70 B/W Refrigerant pressure sensor [Engine is running]
Warm-up condition
Both A/C switch and blower switch: ON
(Compressor operates.)1.0 - 4.0V
73 Y/B Engine coolant temperature
sensor
[Engine is running] Approximately 0 - 4.8V
Output voltage varies with
engine coolant temperature.
74 L Heated oxygen sensor 2
(bank 2) [Engine is running]
Revving engine from idle to 3,000 rpm
quickly after the following conditions are
met.
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load
0 - Approximately 1.0V
78 B/W Sensor ground
(Heated oxygen sensor 2) [Engine is running]
Warm-up condition
Idle speed
Approximately 0V
65
79
80
81 G/R
V/W
W/R
W/G Ignition signal No. 8
Ignition signal No. 6
Ignition signal No. 4
Ignition signal No. 2 [Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle 0 - 0.3V
[Engine is running]
Warm-up condition
Engine speed: 2,500 rpm 0.1 - 0.6V
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
SEC986C
SEC987C
TROUBLE DIAGNOSISEC-115
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Revision: November 2009 2006 QX56
ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
ItemDIAGNOSTIC 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
ENGINE CONTROL COMPONENT PARTS
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
sensor ××
×
Intake air temperature sensor ××××
Knock sensor ×
Refrigerant pressure sensor ××
Closed throttle position switch
(accelerator pedal position sensor
signal) ××
Air conditioner switch ××
Park/neutral position (PNP) switch ×××
Stop lamp switch ×××
Power steering pressure sensor ×××
Battery voltage ××
Load signal ××
Fuel level sensor ×××
ICC steering switch ×××
ASCD steering switch ×××
ICC brake switch ×××
ASCD brake switch ×××
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.
TROUBLE DIAGNOSISEC-119
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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.
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
EC-130Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
LOAD SIGNALIgnition switch: ONRear window defogger switch is ON
and/or lighting switch is in 2nd.
ON
Rear window defogger switch is OFF
and lighting switch is OFF. OFF
IGNITION SW
Ignition switch: ON → OFF → ON ON → OFF → ON
HEATER FAN SW
Engine: After warming up, idle
the engine Heater fan control switch: ON
ON
Heater fan control switch: OFF OFF
BRAKE SW
Ignition switch: ON Brake pedal: Fully released
OFF
Brake pedal: Slightly depressed ON
INJ PULSE-B1
INJ PULSE-B2
Engine: After warming up
Selector lever: P or N
Air conditioner switch: OFF
No load Idle
2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec
IGN TIMING
Engine: After warming up
Selector lever: P or N
Air conditioner switch: OFF
No load Idle
10° - 20 ° BTDC
2,000 rpm 25° - 45 ° BTDC
CAL/LD VALUE
Engine: After warming up
Selector lever: P or N
Air conditioner switch: OFF
No load Idle
14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW
Engine: After warming up
Selector lever: P or N
Air conditioner switch: OFF
No load Idle
3.0 - 9.0 g·m/s
2,500 rpm 9.0 - 28.0 g·m/s
PURG VOL C/V
Engine: After warming up
Selector lever: P or N
Air conditioner switch: OFF
No load Idle
(Accelerator pedal: Not depressed
even slightly, after engine starting.)
0%
2,000 rpm —
AIR COND RLY
Engine: After warming up, idle
the engine Air conditioner switch: OFF
OFF
Air conditioner switch: ON
(Compressor: Operates) ON
FUEL PUMP RLY
For 1 second after turning ignition switch ON
Engine running or cranking ON
Except above conditions
OFF
VENT CONT/V
Ignition switch: ON OFF
THRTL RELAY
Ignition switch: ON ON
COOLING FAN
Engine: After warming up, idle
the engine
Air conditioner switch: OFF Engine coolant temperature: 99
°C
(210 °F) or less OFF
Engine coolant temperature: 100 °C
(212 °F) or more HI
HO2S2 HTR (B1)
HO2S2 HTR (B2)
Engine speed: Below 3,600 rpm after the following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no load ON
Engine speed: Above 3,600 rpm
OFF
I/P PULLY SPD
Vehicle speed: More than 20 km/h (12 MPH) Almost the same speed as the
tachometer indication
MONITOR ITEM CONDITION SPECIFICATION
EC-134Revision: November 2009
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2006 QX56
TROUBLE DIAGNOSIS - SPECIFICATION VALUEPFP:00031
DescriptionUBS00L0F
The specification (SP) value indicates the tolerance of the value that is displayed in “DATA MONITOR (SPEC)”
mode of CONSULT-II during normal operation of the Engine Control System. When the value in “DATA MONI-
TOR (SPEC) ” mode is within the SP value, the Engine Control System is confirmed OK. When the value in
“DATA MONITOR (SPEC) ” mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)
A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionUBS00L0G
Vehicle driven distance: More than 5,000 km (3,107 miles)
Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm2 , 14.25 - 15.12 psi)
Atmospheric temperature: 20 - 30 °C (68 - 86 °F)
Engine coolant temperature: 75 - 95 °C (167 - 203 °F)
Engine speed: Idle
Transmission: Warmed-up
–After the engine is warmed up to normal operating temperature, drive vehicle until “ATF TEMP SE 1” (A/T
fluid temperature sensor signal) indicates more than 60 °C (140 °F).
Electrical load: Not applied
–Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
Inspection ProcedureUBS00L0H
NOTE:
Perform “DATA MONITOR (SPEC) ” mode in maximum scale display.
1. Perform EC-71, "
Basic Inspection" .
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL ”, “A/F ALPHA-B1 ”, “A/F ALPHA-B2 ”
and “MAS A/F SE-B1 ” in “DATA MONITOR (SPEC) ” mode with
CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-135, "
Diagnostic Procedure" .
SEF601Z