fuel consumption INFINITI QX4 2005 Factory Service Manual

EC-104Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
Symptom Matrix ChartUBS00L05
SYSTEM — BASIC ENGINE CONTROL SYSTEM
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
Fuel Fuel pump circuit 1 1 2 3 2 2 2 3 2EC-637
Fuel pressure regulator system 3 3 4 4 4 4 4 4 4 4EC-94
Injector circuit 1 1 2 3 2 2 2 2EC-631
Evaporative emission system 3 3 4 4 4 4 4 4 4 4EC-32
Air Positive crankcase ventilation sys-
tem
334444444 41EC-45
Incorrect idle speed adjustment 1 1 1 1 1EC-72
Electric throttle control actuator 1 1 2 3 3 2 2 2 2 2 2EC-397
,
EC-399
,
EC-405
,
EC-410
Ignition Incorrect ignition timing adjustment 3 3 1 1 1 1 1 1EC-72
Ignition circuit 1 1 2 2 2 2 2 2EC-619
Main power supply and ground circuit 2 2 3 3 3 3 3 2 3EC-157
Mass air flow sensor circuit
1
122
222 2EC-174,
EC-183
Engine coolant temperature sensor circuit
333EC-195,
EC-208
Air fuel ratio (A/F) sensor 1 circuitEC-459
,
EC-468
,
EC-477
,
EC-487
,
EC-497
,
EC-507
,
EC-519
Throttle position sensor circuit
22EC-201
,
EC-264
,
EC-450
,
EC-452
,
EC-604
Accelerator pedal position sensor circuit 3 2 1EC-454
,
EC-591
,
EC-597
,
EC-611
Knock sensor circuit 2 3EC-279
Crankshaft position sensor (POS) circuit 2 2EC-284

TROUBLE DIAGNOSIS
EC-105
C
D
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EC
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
C
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EC
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

LAN-6
[CAN]
CAN COMMUNICATION
Revision: October 20052005 QX56
Input/output signal chart
T: Transmit R: Receive
Signals ECM TCMDriver
seat
con-
trol
unitCom-
bina-
tion
meterDis-
play
con-
trol
unitBCMStee r-
ing
angle
sensorFront
air
control ABS
actua-
tor and
elec-
tric unit
(con-
trol
unit)IPDM
E/R
Engine speed signal T R R R R
Engine status signal T R R
Engine coolant temperature signal T R R R
A/T self-diagnosis signal R T
Accelerator pedal position signal T R R
Closed throttle position signal T R
Wide open throttle position signal T R
Battery voltage signal T R
Key switch signal R T
Ignition switch signal R T R
P range signal T R
Stop lamp switch signal R T
Parking brake switch signal T R
Fuel consumption monitor signalTR
TR
Turbine revolution signal R T
Output shaft revolution signal R T
A/C switch signal R T
A/C compressor request signal T R R
Blower fan motor switch signal R T R
A/C switch/indicator signalTR
RT
Cooling fan speed request signal T R R
Position light request signal R T R
Low beam request signal T R
Low beam status signal RT
High beam request signal R T R
High beam status signal RT
Front fog light request signal T R
Day time running light request signal T R
Vehicle speed signalRRT
RRRTRR R
Sleep wake up signal R T R
Door switch signal R R R T R
Turn indicator signal R T
Key fob ID signal R T
Key fob door unlock signal R T
Buzzer output signal R T

LAN-8
[CAN]
CAN COMMUNICATION
Revision: October 20052005 QX56
TYPE2
System diagram

Type2
Input/output signal chart
T: Transmit R: Receive
PKIA8134E
Signals ECM TCMICC
sen-
sorICC
unitDriver
seat
con-
trol
unitCom-
bina-
tion
mete
rDis-
play
con-
trol
unitBCMSteer-
ing
angle
sensorFront
air
con-
trol ABS
actu-
ator
and
elec-
tric
unit
(con-
trol
unit)IPD
M E/
R
Engine speed signal T R R R R R
Engine status signal T R R
Engine coolant temperature signal T R R R
A/T self-diagnosis signal R T
Accelerator pedal position signal T R R R
Closed throttle position signal T R R
Wide open throttle position signal T R
Battery voltage signal T R
Key switch signal R T
Ignition switch signal R T R
P range signal T R R
Stop lamp switch signal R T
Parking brake switch signal T R
Fuel consumption monitor signalTR
TR
Turbine revolution signal R T R
Output shaft revolution signal R T R
A/C switch signal R T
A/C compressor request signal T R R
Blower fan motor switch signal R T R

CAN COMMUNICATION
LAN-11
[CAN]
C
D
E
F
G
H
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J
L
MA
B
LAN
Revision: October 20052005 QX56
Input/output signal chart
T: Transmit R: Receive
Signals ECM TCMDriver
seat
con-
trol
unitCom-
bina-
tion
meterDis-
play
con-
trol
unitBCMStee r-
ing
angle
sen-
sorFront
air
con-
trolTran s-
fer
con-
trol
unitABS
actua-
tor
and
elec-
tric
unit
(con-
trol
unit)IPDM
E/R
A/T self-diagnosis signal R T
Stop lamp switch signal R T
Parking brake switch signal T R
Battery voltage signal T R
Key switch signal R T
Ignition switch signal R T R
P range signal T R
Closed throttle position signal T R
Wide open throttle position signal T R
Engine speed signal T R R R R R
Engine status signal T R R
Engine coolant temperature signal T R R R
Accelerator pedal position signal T R R R
Fuel consumption monitor signalTR
TR
Turbine revolution signal R T
Output shaft revolution signal R T R
A/C switch signal R T
A/C compressor request signal T R R
Blower fan motor switch signal R T R
A/C switch/indicator signalTR
RT
Cooling fan speed request signal T R R
Position light request signal R T R
Low beam request signal T R
Low beam status signal RT
High beam request signal R T R
High beam status signal RT
Front fog light request signal T R
Day time running light request signal T R
Vehicle speed signalRRRT
RRRT RR R
Sleep wake up signal R T R
Door switch signal R R R T R
Turn indicator signal R T
Key fob ID signal R T
Key fob door unlock signal R T

CAN COMMUNICATION
LAN-13
[CAN]
C
D
E
F
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H
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B
LAN
Revision: October 20052005 QX56
TYPE 4
System diagram

Ty p e 4
Input/output signal chart
T: Transmit R: Receive
PKIA8135E
Signals ECM TCMICC
sen-
sorICC
unitDriver
seat
con-
trol
unitCom-
bina-
tion
mete
rDis-
play
con-
trol
unitBCMStee r-
ing
angle
sen-
sorFront
air
con-
trolTra ns -
fer
con-
trol
unitABS
actu-
ator
and
elec-
tric
unit
(con-
trol
unit)IPD
M
E/R
A/T self-diagnosis signal R T
Stop lamp switch signal R T
Parking brake switch signal T R
Battery voltage signal T R
Key switch signal R T
Ignition switch signal R T R
P range signal T R R
Closed throttle position signal T R R
Wide open throttle position signal T R
Engine speed signal T R R R R R R
Engine status signal T R R
Engine coolant temperature sig-
nalTR R R
Accelerator pedal position signal T R R R R
Fuel consumption monitor signalTR
TR
Turbine revolution signal R T R
Output shaft revolution signal R T R R
A/C switch signal R T
A/C compressor request signal T R R
Blower fan motor switch signal R T R