engine INFINITI QX56 2004 Factory Service Manual

EC-80Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
3. CHECK TARGET IDLE SPEED
With CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no
load, then run engine at idle speed for about 1 minute.
3. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Without CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no load, then run engine at idle speed for about
1 minute.
3. Check idle speed.
OK or NG
OK >> GO TO 9.
NG >> GO TO 4.
4. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-44, "
Accelerator Pedal Released Position Learning" .
>> GO TO 5.
5. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-44, "
Throttle Valve Closed Position Learning" .
>> GO TO 6.
SEF 9 78 U
650 ± 50 rpm (in P or N position)
SEF 0 58 Y
650 ± 50 rpm (in P or N position)

TROUBLE DIAGNOSIS
EC-81
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: August 20072004 QX56
6. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-44, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 7.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
7. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
OK or NG
OK >> GO TO 10.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.

Check camshaft position sensor (PHASE) and circuit. Refer to EC-261 .

Check crankshaft position sensor (POS) and circuit. Refer to EC-255 .
OK or NG
OK >> GO TO 9.
NG >> 1. Repair or replace.
2. GO TO 4.
9. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-138, "
IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS)" .
>> GO TO 4. 650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)

EC-82Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
10. CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light.
OK or NG
OK >>INSPECTION END
NG >> GO TO 11.
11 . PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-44, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-44, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-44, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 14.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
14. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.15 ± 5° BTDC (in P or N position)
BBIA0379E
650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)

TROUBLE DIAGNOSIS
EC-83
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: August 20072004 QX56
15. CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light.
OK or NG
OK >>INSPECTION END
NG >> GO TO 16.
16. CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-35, "
TIMING CHAIN" .
OK or NG
OK >> GO TO 17.
NG >> 1. Repair the timing chain installation.
2. GO TO 4.
17. DETECT MALFUNCTIONING PART
Check the following.

Check camshaft position sensor (PHASE) and circuit. Refer to EC-261 .

Check crankshaft position sensor (POS) and circuit. Refer to EC-255 .
OK or NG
OK >> GO TO 18.
NG >> 1. Repair or replace.
2. GO TO 4.
18. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-138, "
IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS)" .
>> GO TO 4. 15 ± 5° BTDC (in P or N position)
BBIA0379E

EC-84Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
Symptom Matrix ChartUBS00H00
SYSTEM — BASIC ENGINE CONTROL SYSTEM
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
Fuel Fuel pump circuit 1 1 2 3 2 2 2 3 2EC-601
Fuel pressure regulator system 3 3 4 4 4 4 4 4 4 4EC-46
Injector circuit 1 1 2 3 2 2 2 2EC-595
Evaporative emission system 3 3 4 4 4 4 4 4 4 4EC-633
Air Positive crankcase ventilation sys-
tem
334444444 41EC-645
Incorrect idle speed adjustment 1 1 1 1 1EC-79
Electric throttle control actuator 1 1 2 3 3 2 2 2 2 2 2EC-365,
EC-367
Ignition Incorrect ignition timing adjustment 3 3 1 1 1 1 1 1EC-79
Ignition circuit 1 1 2 2 2 2 2 2EC-583
Main power supply and ground circuit 2 2 3 3 3 3 3 2 3EC-128
Mass air flow sensor circuit
1
122
222 2EC-146,
EC-154
Engine coolant temperature sensor circuit
333EC-165,
EC-178
A/F sensor 1 circuitEC-429
,
EC-437
,
EC-445
,
EC-454
,
EC-463
,
EC-472
,
EC-484
Throttle position sensor circuit
22EC-171
,
EC-236
,
EC-420
,
EC-422
,
EC-569
Accelerator pedal position sensor circuit 3 2 1EC-424
,
EC-556
,
EC-562
,
EC-576
Knock sensor circuit 2 3EC-250
Crankshaft position sensor (POS) circuit 2 2EC-255
Camshaft position sensor (PHASE) circuit 3 2EC-261

TROUBLE DIAGNOSIS
EC-85
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: August 20072004 QX56
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Vehicle speed signal circuit 2 3 3 3EC-340
Power steering pressure sensor circuit 2 3 3EC-346
ECM 22333333333EC-351,
EC-361
PNP switch circuit 3 3 3 3 3EC-546
Refrigerant pressure sensor circuit 2 3 3 4EC-607
Electrical load signal circuit 3EC-612
Air conditioner circuit 2 2 3 3 3 3 3 3 3 3 2AT C - 3 3
ABS actuator and electric unit (control unit) 4BRC-11
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
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
Fuel Fuel tank
5
5FL-9
Fuel piping 5 5 5 5 5 5FL-3
Vapor lock—
Valve deposit
555555 5—
Poor fuel (Heavy weight gaso-
line, Low octane)—

EC-86Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
Air Air duct
55555 5EM-14
Air cleanerEM-14
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555EM-14
Electric throttle control actuatorEM-15
Air leakage from intake manifold/
Collector/GasketEM-15
Cranking Battery
111111
11SC-4
Generator circuitSC-17
Starter circuit 3SC-10
Signal plate 6EM-15
PNP switch 4AT- 1 0 9
Engine Cylinder head
55555 55 5EM-59
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-73
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va lv e
mecha-
nismTiming chain
55555 55 5EM-35
CamshaftEM-43
Intake valve
3EM-59
Exhaust valve
Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5EM-19
, EX-
3Three way catalyst
Lubrica-
tionOil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5EM-22
, LU-
10 , LU-11
, LU-13
Oil level (Low)/Filthy oilLU-7
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

TROUBLE DIAGNOSIS
EC-87
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: August 20072004 QX56
1 - 6: The numbers refer to the order of inspection.Cooling Radiator/Hose/Radiator filler cap
55555 55 45CO-10
Thermostat 5CO-17
Water pum pCO-15
Water galleryCO-6
Cooling fan
5EC-410
Coolant level (Low)/Contami-
nated coolantCO-8
IVIS (Infinti Vehicle Immobilizer System —
NATS)11EC-63 or
BL-138
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-88Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
Engine Control Component Parts LocationUBS00H01
BBIA0449E

EC-96Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
ECM Harness Connector Terminal LayoutUBS00H03
ECM Terminals and Reference ValueUBS00H04
PREPARATION
1. ECM is located in the engine room passenger side behind bat-
tery.
2. Remove ECM harness connector.
3. When disconnecting ECM harness connector, loosen it with
levers as far as they will go as shown in the figure.
4. Connect a break-out box (SST) and Y-cable adapter (SST)
between the ECM and ECM harness connector.

Use extreme care not to touch 2 pins at one time.

Data is for comparison and may not be exact.
ECM INSPECTION TABLE
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECMs transistor. Use a ground other than ECM terminals, such as the ground.
PBIB1192E
BBIA0386E
BBIA0387E
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1 B ECM ground[Engine is running]

Idle speedBody ground
2O/BA/F sensor 1 heater
(bank 1)[Engine is running]

Warm-up condition

Idle speedApproximately 5V
PBIB1584E