2005 INFINITI QX4 engine

TROUBLE DIAGNOSIS
EC-105
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Revision: October 20052005 QX56
1 - 6: The numbers refer to the order of inspection.
(continued on next page)Camshaft position sensor (PHASE) circuit 3 2EC-291
Vehicle speed signal circuit 2 3 3 3EC-372
Power steering pressure sensor circuit 2 3 3EC-378
ECM 22333333333EC-383,
EC-393
Park/Neutral position (PNP) switch circuit 3 3 3 3 3EC-581
Refrigerant pressure sensor circuit 2 3 3 4EC-643
Electrical load signal circuit 3EC-648
Air conditioner circuit 2 2 3 3 3 3 3 3 3 3 2AT C - 3 3
ABS actuator and electric unit (control unit) 4EC-438
,
EC-439

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

EC-106Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
SYSTEM — ENGINE MECHANICAL & OTHER
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
Va p o r lo c k—
Valve deposit
555555 5—
Poor fuel (Heavy weight gaso-
line, Low octane)—
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-35
Park/Neutral position (PNP)
switch4AT- 1 0 4
Engine Cylinder head
55555 55 5EM-58
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-58
Exhaust valve

TROUBLE DIAGNOSIS
EC-107
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Revision: October 20052005 QX56
1 - 6: The numbers refer to the order of inspection.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-
13 , LU-10 ,
LU-11
Oil level (Low)/Filthy oilLU-7
Cooling Radiator/Hose/Radiator filler cap
55555 55 45CO-12
Thermostat 5CO-19
Water pum pCO-17
Water galleryCO-8
Cooling fan 5CO-15
Coolant level (Low)/Contami-
nated coolant5CO-10
IVIS (INFINITI Vehicle Immobilizer System —
NATS)11BL-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-108Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
Engine Control Component Parts LocationUBS00L06
BBIA0449E

TROUBLE DIAGNOSIS
EC-117
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Revision: October 20052005 QX56
ECM Harness Connector Terminal LayoutUBS00L09
ECM Terminals and Reference ValueUBS00L0A
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.
MBIB0045E
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

EC-118Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
3LThrottle control motor relay
power supply[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle control motor (Close)[Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully released0 - 14V
5 L/B Throttle control motor (Open)[Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully depressed0 - 14V
6GRHeated oxygen sensor 2
heater (bank 1)[Engine is running]

Warm-up condition

Engine speed is below 3,600 rpm after the
following conditions are met.
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load0 - 1.0V
[Ignition switch: ON]

Engine: Stopped
[Engine is running]

Engine speed: Above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
12 RPower steering pressure sen-
sor[Engine is running]

Steering wheel: Being turned0.5 - 4.5V
[Engine is running]

Steering wheel: Not being turned0.4 - 0.8V
13 OCrankshaft position sensor
(POS)[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idleApproximately 10V
[Engine is running]

Engine speed: 2,000 rpmApproximately 10V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB1104E
PBIB1105E
PBIB1041E
PBIB1042E

TROUBLE DIAGNOSIS
EC-119
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Revision: October 20052005 QX56
14 YCamshaft position sensor
(PHASE)[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle1.0 - 4.0V
[Engine is running]

Engine speed: 2,000 rpm1.0 - 4.0V
15 W Knock sensor (bank 1)[Engine is running]

Idle speedApproximately 2.5V
16 BR/R
A/F sensor 1 (bank 1)[Engine is running]

Warm-up condition

Idle speedApproximately 3.1V
35 BR/GApproximately 2.6V
56 LG/BApproximately 2.3V
75 P/BApproximately 2.3V
21
22
23
44O/L
BR
GR/W
OInjector No. 5
Injector No. 3
Injector No. 1
Injector No. 7[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idleBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Warm-up condition

Engine speed: 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
24 BR/WA/F sensor 1 heater
(bank 2)[Engine is running]

Warm-up condition

Idle speedApproximately 5V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB1039E
PBIB1040E
SEC984C
SEC985C
PBIB1584E

EC-120Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
25 O/GHeated oxygen sensor 2
heater (bank 2)[Engine is running]

Warm-up condition

Engine speed is below 3,600 rpm after the
following conditions are met.
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load0 - 1.0V
[Ignition switch: ON]

Engine: Stopped
[Engine is running]

Engine speed: Above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
32 LEVAP control system pres-
sure sensor[Ignition switch: ON]Approximately 1.8 - 4.8V
34 R/B Intake air temperature sensor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with intake
air temperature.
36 W Knock sensor (bank 2)[Engine is running]

Idle speedApproximately 2.5V
40
41
42
63Y/G
P
L
GInjector No. 6
Injector No. 4
Injector No. 2
Injector No. 8[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idleBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Warm-up condition

Engine speed: 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
45 L/YEVAP canister purge volume
control solenoid valve[Engine is running]

Idle speed

Accelerator pedal: Not depressed even
slightly, after engine startingBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Engine speed: About 2,000 rpm (More than
100 seconds after starting engine)BATTERY VOLTAGE
(11 - 14V) TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
SEC984C
SEC985C
SEC990C
SEC991C