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-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
TROUBLE DIAGNOSISEC-121
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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
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-124Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
*: 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-54, "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.
DTC WORK SUPPORT Mode
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.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
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
Test mode
Test itemCorresponding DTC No. Reference page
EVAPORATIVE
SYSTEM PURG FLOW P0441
P0441EC-360
EVP SML LEAK P0442/P1442* P0442
EC-365P0455EC-419
EVP V/S LEAK P0456/P1456* P0456EC-427
PURG VOL CN/V P1444 P0443EC-373
A/F SEN1 A/F SEN1 (B1) P1276
P0130EC-213A/F SEN1 (B1) P1278/P1279 P0133EC-241
A/F SEN1 (B2) P1286 P0150EC-213
A/F SEN1 (B2) P1288/P1289 P0153EC-241
HO2S2 HO2S2 (B1) P0139
P0139EC-277
HO2S2 (B1) P1146 P0138EC-264
HO2S2 (B1) P1147 P0137EC-253
HO2S2 (B2) P0159 P0159EC-277
HO2S2 (B2) P1166 P0158EC-264
HO2S2 (B2) P1167 P0157EC-253
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-192Revision: November 2009
DTC P0117, P0118 ECT SENSOR
2006 QX56
DTC P0117, P0118 ECT SENSORPFP:22630
Component DescriptionUBS00H1J
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.
*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis LogicUBS00H1K
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
SEF594K
Engine coolant temperature°C (°F) Voltage* V
Resistance kΩ
– 10 (14) 4.47.0 - 11.4
20 (68) 3.52.1 - 2.9
50 (122) 2.20.68 - 1.00
90 (194) 0.90.236 - 0.260
SEF012P
DTC
No. Trouble Diagnosis Name
DTC Detecting Condition Possible Cause
P0117
0117 Engine coolant temperature
sensor circuit low input An excessively low voltage from the sensor is
sent to ECM.
Harness or connectors
(The sensor circuit is open or shorted.)
Engine coolant temperature sensor
P0118
0118 Engine coolant temperature
sensor circuit high input An excessively high voltage from the sensor is
sent to ECM.
Detected items
Engine operating condition in fail-safe mode
Engine coolant temper- ature sensor circuit Engine coolant temperature will be determined by ECM based on the time after turning ignition switch ON
or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned ON or START 40°C (104 °F)
More than approx. 4 minutes after ignition ON or
START 80
°C (176 °F)
Except as shown above 40 - 80
°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling fan operates
while engine is running.
EC-444Revision: November 2009
DTC P0506 ISC SYSTEM
2006 QX56
DTC P0506 ISC SYSTEMPFP:23781
DescriptionUBS00H6H
NOTE:
If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis LogicUBS00H6I
DTC Confirmation ProcedureUBS00H6J
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
If the target idle speed is out of the specified value, perform EC-78, "Idle Air Volume Learning" ,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-637,
"SERVICE DATA AND SPECIFICATIONS (SDS)" .
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
Always perform the test at a temperature above −10 °C (14 °F).
WITH CONSULT-II
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON again and select “DATA MONITOR”
mode with CONSULT-II.
5. Start engine and run it for at least 1 minute at idle speed.
6. If 1st trip DTC is detected, go to EC-445, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0506
0506 Idle speed control system
RPM lower than expected The idle speed is less than the target idle
speed by 100 rpm or more.
Electric throttle control actuator
Intake air leak
SEF174Y