Page 1161 of 3383
DI-40
WARNING LAMPS
Revision: November 20092006 QX56
Oil Pressure Warning Lamp Does Not Turn Off (Oil Pressure Is Normal)EKS00BCL
NOTE:
For oil pressure inspection, refer to LU-7, "
OIL PRESSURE CHECK" .
1. CHECK ENGINE OIL PRESSURE GAUGE OPERATION
Observe operation of engine oil pressure gauge.
Does engine oil pressure gauge function properly?
YES >> Replace the combination meter. Refer to IP-13, "COMBINATION METER" .
NO >> Go to DI-19, "
Engine Oil Pressure Signal Inspection" .
Page 1228 of 3383

PRECAUTIONSEC-17
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Do not disassemble ECM.
If a battery cable is disconnected, the memory will return to
the ECM value.
The ECM will now start to self-control at its initial value.
Engine operation can vary slightly when the terminal is dis-
connected. However, this is not an indication of a malfunc-
tion. Do not replace parts because of a slight variation.
If the battery is disconnected, the following emission-
related diagnostic information will be lost within 24 hours.
–Diagnostic trouble codes
–1st trip diagnostic trouble codes
–Freeze frame data
–1st trip freeze frame data
–System readiness test (SRT) codes
–Test values
When connecting ECM harness connector, fasten it
securely with a lever as far as it will go as shown in the fig-
ure.
When connecting or disconnecting pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM
pin terminal, when connecting pin connectors.
Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge)
voltage to develop in coil and condenser, thus resulting in
damage to ICs.
Keep engine control system harness at least 10 cm (4 in)
away from adjacent harness, to prevent engine control sys-
tem malfunctions due to receiving external noise, degraded
operation of ICs, etc.
Keep engine control system parts and harness dry.
Before replacing ECM, perform ECM Terminals and Refer-
ence Value inspection and make sure ECM functions prop-
erly. Refer to EC-105, "
ECM Terminals and Reference Value"
.
Handle mass air flow sensor carefully to avoid damage.
Do not disassemble mass air flow sensor.
Do not clean mass air flow sensor with any type of deter-
gent.
Do not disassemble electric throttle control actuator.
Even a slight leak in the air intake system can cause seri-
ous incidents.
Do not shock or jar the camshaft position sensor (PHASE), crankshaft position sensor (POS).
PBIB1164E
BBIA0387E
PBIB0090E
MEF040D
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BASIC SERVICE PROCEDUREEC-77
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2. Connect ignition coil No.1 and spark plug with suitable high-ten-
sion wire as shown, and attach timing light clamp to this wire.
3. Check ignition timing.
VIN RegistrationUBS00KZX
DESCRIPTION
VIN Registration is an operation to registering VIN in ECM. It must be performed each time ECM is replaced.
NOTE:
Accurate VIN which is registered in ECM may be required for Inspection & Maintenance (I/M).
OPERATION PROCEDURE With CONSULT-II
1. Check the VIN of the vehicle and note it. Refer to GI-47, "IDENTIFICATION INFORMATION" .
2. Turn ignition switch ON and engine stopped.
3. Select “VIN REGISTRATION ” in “WORK SUPPORT ” mode.
4. Follow the instruction of CONSULT-II display.
BBIA0378E
SEF011V
BBIA0379E
PBIB2242E
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EC-92Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
Symptom Matrix ChartUBS00L05
SYSTEM — BASIC ENGINE CONTROL SYSTEM
SYMPTOMRefer-
ence 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
Fuel Fuel pump circuit 11232 22 3 2EC-604
Fuel pressure regulator system 334444444 4 EC-82
Injector circuit11232 22 2EC-598
Evaporative emission system 334444444 4 EC-32
Air Positive crankcase ventilation sys-
tem 334444444 41
EC-45
Incorrect idle speed adjustment 1 1 1 1 1EC-71
Electric throttle control actuator 112332222 2 2 EC-528
,
EC-534
,
EC-540
,
EC-545
IgnitionIncorrect ignition timing adjustment 33111 11 1EC-71
Ignition circuit 11222 22 2EC-618
Main power supply and ground circuit 22333 33 23 EC-145
Mass air flow sensor circuit
1
12 2
222 2 EC-171,
EC-180
Engine coolant temperature sensor circuit
333
EC-192,
EC-205
Air fuel ratio (A/F) sensor 1 circuit EC-213
,
EC-223
,
EC-232
,
EC-241
,
EC-575
Throttle position sensor circuit 22EC-198
,
EC-320
,
EC-483
,
EC-485
,
EC-560
Accelerator pedal position sensor circuit 3 2 1EC-453
,
EC-547
,
EC-553
,
EC-567
Knock sensor circuit 23EC-335
Crankshaft position sensor (POS) circuit 2 2 EC-340
Camshaft position sensor (PHASE) circuit 3 2EC-347
Page 1304 of 3383
TROUBLE DIAGNOSISEC-93
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1 - 6: The numbers refer to the order of inspection.
(continued on next page)Vehicle speed signal circuit
2 3 33EC-442
Power steering pressure sensor circuit 23 3 EC-448
ECM 22333333333 EC-453,
EC-457
Park/Neutral position (PNP) switch circuit 3 3 3 33EC-465
Refrigerant pressure sensor circuit 233 4 EC-630
Electrical load signal circuit 3EC-596
Air conditioner circuit 223333333 3 2 AT C - 3 4
ABS actuator and electric unit (control unit)4EC-471
,
EC-472
or BRC-11
SYMPTOM
Refer-
ence 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
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EC-94Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
SYSTEM — ENGINE MECHANICAL & OTHER
SYMPTOMReference
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
Fuel Fuel tank 5
5 FL-10
Fuel piping
5 5 5 5 55FL-4
Vapor lock —
Valve deposit 5 555 55 5 —
Poor fuel (Heavy weight gaso-
line, Low octane) —
Air Air duct
55555 5 EM-15
Air cleaner
EM-15
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator) 5555 EM-15
Electric throttle control actuator
EM-17
Air leakage from intake manifold/
Collector/GasketEM-17
Cranking Battery
111111
11
SC-4
Generator circuit
SC-17
Starter circuit3 SC-10
Signal plate6 EM-37
Park/Neutral position (PNP)
switch4
AT- 1 0 5
Engine Cylinder head
55555 55 5EM-63
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-78
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nism Timing chain
55555 55 5 EM-37
Camshaft
EM-46
Intake valve
3EM-63
Exhaust valve
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TROUBLE DIAGNOSISEC-95
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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
Page 1334 of 3383

TROUBLE DIAGNOSISEC-123
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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