PRECAUTIONS
EC-25
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Revision: 2007 April2007 M35/M45
PrecautionNBS004RZ
Always use a 12 volt battery as power source.
Do not attempt to disconnect battery cables while engine is
running.
Before connecting or disconnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect negative
battery cable. Failure to do so may damage the ECM
because battery voltage is applied to ECM even if ignition
switch is turned OFF.
Before removing parts, turn ignition switch OFF and then
disconnect negative battery cable.
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 (B) it
securely with a lever (2) as far as it will go as shown in the
figure.
–ECM (1)
–Loosen (A)
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.
SEF289H
PBIB1164E
PBIB2714E
PBIB0090E
TROUBLE DIAGNOSIS
EC-99
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Revision: 2007 April2007 M35/M45
Symptom Matrix ChartNBS004T1
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 11232 22 3 2EC-675
Fuel pressure regulator system334444444 4EC-88
Fuel injector circuit 11232 22 2EC-669
Evaporative emission system334444444 4EC-39
Air Positive crankcase ventilation sys-
tem
334444444 41EC-51
Incorrect idle speed adjustment 1 1 1 1 1EC-78
Electric throttle control actuator 112332222 2 2EC-
604,EC-
598 ,EC-
610 ,EC-
615
IgnitionIncorrect ignition timing adjustment33111 11 1EC-78
Ignition circuit 11222 22 2EC-691
Main power supply and ground circuit22333 33 23EC-154
Mass air flow sensor circuit
1
122
222 2EC-193,
EC-202
Engine coolant temperature sensor circuit
333EC-214,
EC-226
Air fuel ratio (A/F) sensor 1 circuitEC-234
,
EC-244
,
EC-253
,
EC-262
,
EC-646
Throttle position sensor circuit
22EC-219
,
EC-342
,
EC-518
,
EC-520
,
EC-631
Accelerator pedal position sensor circuit 3 2 1EC-
617,EC-
624 ,EC-
638 ,EC-
486
Knock sensor circuit 2 3EC-359
Crankshaft position sensor (POS) circuit 2 2EC-364
EC-100
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TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
1 - 6: The numbers refer to the order of inspection.
(continued on next page)Camshaft position sensor (PHASE) circuit 3 2EC-371
Vehicle speed signal circuit 2 3 3 3EC-468
Power steering pressure sensor circuit 2 3 3EC-474
ECM 22333333333EC-479,
EC-483
Intake valve timing control solenoid valve cir-
cuit32 13223 3EC-185
PNP switch circuit 3 3 3 3 3EC-491
Refrigerant pressure sensor circuit 2 3 3 4EC-704
Electrical load signal circuit 3EC-667
Air conditioner circuit 223333333 3 2AT C - 4 0
ABS actuator and electric unit (control unit) 4BRC-10
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-101
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Revision: 2007 April2007 M35/M45
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-10
Fuel piping 5 5 5 5 5 5EM-47
Vapor lock—
Valve deposit
5 555 55 5—
Poor fuel (Heavy weight gaso-
line, Low octane)—
Air Air duct
55555 5EM-19
Air cleanerEM-19
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555EM-19
Electric throttle control actuatorEM-21
Air leakage from intake manifold/
Collector/GasketEM-26
Cranking Battery
111111
11SC-4
Generator circuitSC-20
Starter circuit 3SC-8
Signal plate 6EM-124
PNP switch 4AT- 11 3
Engine Cylinder head
55555 55 5EM-102
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-124
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nismTiming chain
55555 55 5EM-66
CamshaftEM-85
Intake valve timing controlEM-66
Intake valve
3EM-85
Exhaust valve
EC-102
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TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
1 - 6: The numbers refer to the order of inspection.Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5EM-28
, EX-
3Three way catalyst
Lubrica-
tionOil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5EM-31
, LU-
19 , LU-11 ,
LU-15
Oil level (Low)/Filthy oilLU-7
Cooling
Radiator/Hose/Radiator filler cap
55555 55 45CO-14,
CO-18
Thermostat 5CO-29
Water pumpCO-24
Water galleryCO-31
Cooling fan
5CO-22
Coolant level (Low)/Contami-
nated coolantCO-11
IVIS (INFINITI Vehicle Immobilizer System —
NATS)11EC-53 or
BL-244
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-103
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Revision: 2007 April2007 M35/M45
Engine Control Component Parts LocationNBS004T2
1. IPDM E/R 2. ICC brake hold relay
(ICC models only)3. Battery current sensor
4. Cooling fan relay 5. Power steering pressure sensor 6. Refrigerant pressure sensor
7. Intake valve timing control solenoid
valve (bank 1)8. Cooling fan motor-2 9. Cooling fan control module
10. Intake valve timing control solenoid
valve (bank 2)11. Cooling fan motor-1 12. Mass air flow sensor
(with built in intake air temperature
sensor)
13. Ignition coil (with power transistor)
and spark plug (bank 2)14. Camshaft position sensor (PHASE)
(Bank 2)15. Electric throttle control actuator
(with built in throttle position sensor,
throttle control motor)
16. Fuel injector (bank 2) 17. Knock sensor 18. Fuel injector (bank 1)
19. EVAP canister purge volume con-
trol solenoid valve20. Camshaft position sensor (PHASE)
(Bank 1)21. Engine coolant temperature sensor
22. Ignition coil (with power transistor)
and spark plug (bank 1)23. EVAP service port
PBIB2781E
EC-132
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TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
ACTIVE TEST MODE
Test Item
TEST ITEM CONDITION JUDGEMENT CHECK 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
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 listen 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
FUEL/T TEMP
SEN
Change the fuel tank temperature using CONSULT-II.
VENT CON-
TROL/V
Ignition switch: ON (Engine
stopped)
Turn solenoid valve ”ON” and
”OFF” with the CONSULT-II and
listen to operating sound.Solenoid valve makes an operating
sound.Harness and connectors
Solenoid valve
FPCM
Engine: Returns to the original
trouble condition
Select “LOW” and “HI” with CON-
SULT-II.If trouble symptom disappears, see
CHECK ITEM.
Harness and connectors
FPCM
V/T ASSIGN
ANGLE
Engine: Return to the original
trouble condition
Change intake valve timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
Harness and connectors
Intake valve timing control sole-
noid valve
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-147
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Revision: 2007 April2007 M35/M45
5. CHANGE ENGINE OIL
1. Stop the engine.
2. Change engine oil.
NOTE:
This symptom may occur when a large amount of gasoline is mixed with engine oil because of driving
conditions (such as when engine oil temperature does not rise enough since a journey distance is too
short during winter). The symptom will not be detected after changing engine oil or changing driving con-
dition.
>>INSPECTION END
6. CHECK FUEL PRESSURE
Check fuel pressure. (Refer to EC-88, "
Fuel Pressure Check" .)
OK or NG
OK >> GO TO 9.
NG (Fuel pressure is too high)>>Replace fuel pressure regulator, refer to EC-89, "
FUEL PRESSURE
CHECK" . GO TO 8.
NG (Fuel pressure is too low)>>GO TO 7.
7. DETECT MALFUNCTIONING PART
1. Check the following.
–Clogged and bent fuel hose and fuel tube
–Clogged fuel filter
–Fuel pump and its circuit (Refer to EC-675, "FUEL PUMP" .)
2. If NG, repair or replace the malfunctioning part. (Refer to EC-89, "
FUEL PRESSURE CHECK" .)
If OK, replace fuel pressure regulator.
>> GO TO 8.
8. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 9.
9. PERFORM POWER BALANCE TEST
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Make sure that the each cylinder produces a momentary engine
speed drop.
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
PBIB0133E