Page 1297 of 3419

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
Page 1298 of 3419

TROUBLE DIAGNOSIS
EC-107
C
D
E
F
G
H
I
J
K
L
MA
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
Page 1299 of 3419
EC-108Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
Engine Control Component Parts LocationUBS00L06
BBIA0449E
Page 1300 of 3419
TROUBLE DIAGNOSIS
EC-109
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
BBIA0447E
Page 1301 of 3419
EC-110Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
BBIA0382E
Page 1302 of 3419
TROUBLE DIAGNOSIS
EC-111
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
BBIA0448E
Page 1303 of 3419
EC-112Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
BBIA0384E
Page 1304 of 3419
TROUBLE DIAGNOSIS
EC-113
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
PBIB2639E