2004 INFINITI FX35 Fuel System

ENGINE CONTROL SYSTEM
EC-681
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Revision: 2004 November 2004 FX35/FX45
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all eight cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The eight injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.
Electronic Ignition (EI) SystemABS00BZ7
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The ignition timing is controlled by the ECM to maintain the best air-
fuel ratio for every running condition of the engine. The ignition tim-
ing data is stored in the ECM. This data forms the map shown.
The ECM receives information such as the injection pulse width and
camshaft position sensor signal. Computing this information, ignition
signals are transmitted to the power transistor.
e.g., N: 1,800 rpm, Tp: 1.50 msec
A °BTDC
During the following conditions, the ignition timing is revised by the
ECM according to the other data stored in the ECM.

At starting

During warm-up
PBIB0122E
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
2
Piston position
Ignition timing
controlPower transistor Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor*1Vehicle speed
SEF742M

EC-682
[VK45DE]
ENGINE CONTROL SYSTEM
Revision: 2004 November 2004 FX35/FX45

At idle

At low battery voltage

During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Nissan Torque Demand (NTD) Control SystemABS00BZ8
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
NTD control system decides the target traction based on the accelerator operation status and the current driv-
ing condition. It then selects the engine torque target by correcting running resistance and atmospheric pres-
sure, and controlling the power-train. Using electric throttle control actuator, it achieves the engine torque
development target which corresponds linearly to the driver's accelerator operation.
Running resistance correction control compares the engine torque estimate value, measured vehicle acceler-
ation, and running resistance on a flat road, and estimates vehicle weight gain and running resistance varia-
tion caused by slopes to correct the engine torque estimate value.
Atmospheric pressure correction control compares the engine torque estimate value from the airflow rate and
the target engine torque for the target traction, and estimates variation of atmospheric pressure to correct the
target engine torque. This system achieves powerful driving without reducing engine performance in the prac-
tical speed range in mountains and high-altitude areas.
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
NTD controlElectric throttle con-
trol actuator and fuel
injector Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/Neutral position (PNP) switch Gear position
Power steering pressure sensor Power steering operation
Battery Battery voltage
TCM (CAN communication) A/T control signal
Air conditioner switch* Air conditioner operation
ABS actuator and electric unit (control unit)* VDC/TCS/ABS operation
Wheel sensor* Vehicle speed
Electrical load* Electrical load signal

ENGINE CONTROL SYSTEM
EC-683
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Revision: 2004 November 2004 FX35/FX45
Air Conditioning Cut ControlABS00BZ9
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.

When the accelerator pedal is fully depressed.

When cranking the engine.

At high engine speeds.

When the engine coolant temperature becomes excessively high.

When operating power steering during low engine speed or low vehicle speed.

When engine speed is excessively low.

When refrigerant pressure is excessively low or high.
Fuel Cut Control (at No Load and High Engine Speed)ABS00BZA
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,400 rpm under no load (for example, the shift position is neutral and engine
speed is over 1,400 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies
based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,000 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under Multiport Fuel Injection (MFI) System, EC-679
.
Sensor Input signal to ECM ECM function Actuator
Air conditioner switch*
1Air conditioner ON signal
Air conditioner
cut controlAir conditioner relay Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
2
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor*
1Vehicle speed
Sensor Input signal to ECM ECM function Actuator
Park/neutral position (PNP) switch Neutral position
Fuel cut control Fuel injector Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed
Wheel sensor* Vehicle speed

BASIC SERVICE PROCEDURE
EC-687
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Revision: 2004 November 2004 FX35/FX45
Idle Speed/Ignition Timing/Idle Mixture Ratio AdjustmentABS00BZD
PREPARATION
1. Make sure that the following parts are in good order.

Battery

Ignition system

Engine oil and coolant levels

Fuses

ECM harness connector

Va c u u m h o s e s

Air intake system
(Oil filler cap, oil level gauge, etc.)

Fuel pressure

Engine compression

Throttle valve

Evaporative emission system
2. On air conditioner equipped models, checks should be carried out while the air conditioner is OFF.
3. On automatic transmission equipped models, when checking idle rpm, ignition timing and mixture ratio,
checks should be carried out while shift lever is in N position.
4. When measuring CO percentage, insert probe more than 40 cm (15.7 in) into tail pipe.
5. Turn OFF headlamp, heater blower, rear window defogger.
6. Keep front wheels pointed straight ahead.

BASIC SERVICE PROCEDURE
EC-701
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Revision: 2004 November 2004 FX35/FX45
2. Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT”
mode with CONSULT-II.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel
pressure.
5. Turn ignition switch OFF.
Without CONSULT-II
1. Remove fuel pump fuse located in IPDM E/R.
2. Start engine.
3. After engine stalls, crank it 2 or 3 times to release all fuel pres-
sure.
4. Turn ignition switch OFF.
5. Reinstall fuel pump fuse after servicing fuel system.
FUEL PRESSURE CHECK
Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.
NOTE:

Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel
pressure cannot be completely released because S50 models do not have fuel return system.

Use Fuel Pressure Gauge Kit (J-44321) to check fuel pressure.
1. Release fuel pressure to zero. Refer to EC-700, "
FUEL PRESSURE RELEASE" .
2. Install the inline fuel quick disconnected fitting between fuel
damper and injector tube.
3. Connect the fuel pressure test gauge (quick connector adapter
hose) to the inline fuel quick disconnected fitting.
4. Turn ignition switch ON and check for fuel leakage.
5. Start engine and check for fuel leakage.
6. Read the indication of fuel pressure gauge.
7. If result is unsatisfactory, go to next step.
8. Check the following.

Fuel hoses and fuel tubes for clogging

Fuel filter for clogging

Fuel pump

Fuel pressure regulator for clogging
SEF214Y
PBIB1482E
PBIB1489E
At idling:
Approximately 350 kPa (3.57 kg/cm2 , 51 psi)
PBIB1490E

EC-704
[VK45DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2004 November 2004 FX35/FX45
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands the
driver to repair the malfunction.
Emission-related Diagnostic InformationABS00BZK
EMISSION-RELATED DIAGNOSTIC INFORMATION ITEMS
×: Applicable —: Not applicable Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
Items
(CONSULT-II screen terms)DTC*
1
SRT codeTest value/
Te s t l i m i t
(GST only)1st trip DTCReference
page CONSULT-II
GST*
2ECM*3
CAN COMM CIRCUIT U1000
1000*4———EC-792
CAN COMM CIRCUIT U1001
1001*4——×EC-792
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.P0000 0000————
INT/V TIM CONT-B1 P0011 0011 — —×EC-795
INT/V TIM CONT-B2 P0021 0021 — —×EC-795
HO2S1 HTR (B1) P0031 0031×××EC-806
HO2S1 HTR (B1) P0032 0032×××EC-806
HO2S2 HTR (B1) P0037 0037×××EC-814
HO2S2 HTR (B1) P0038 0038×××EC-814
HO2S1 HTR (B2) P0051 0051×××EC-806
HO2S1 HTR (B2) P0052 0052×××EC-806
HO2S2 HTR (B2) P0057 0057×××EC-814
HO2S2 HTR (B2) P0058 0058×××EC-814
MAF SEN/CIRCUIT P0101 0101 — — —EC-822
MAF SEN/CIRCUIT P0102 0102 — — —EC-830
MAF SEN/CIRCUIT P0103 0103 — — —EC-830
IAT SEN/CIRCUIT P0112 0112 — —×EC-837
IAT SEN/CIRCUIT P0113 0113 — —×EC-837
ECT SEN/CIRCUIT P0117 0117 — — —EC-842
ECT SEN/CIRCUIT P0118 0118 — — —EC-842
TP SEN 2/CIRC P0122 0122 — — —EC-848
TP SEN 2/CIRC P0123 0123 — — —EC-848
ECT SENSOR P0125 0125 — — —EC-855
IAT SENSOR P0127 0127 — —×EC-858
THERMSTAT FNCTN P0128 0128 — —×EC-861
HO2S1 (B1) P0132 0132 —××EC-863
HO2S1 (B1) P0133 0133×××EC-872
HO2S1 (B1) P0134 0134 —××EC-884
HO2S2 (B1) P0138 0138 —××EC-894
HO2S2 (B1) P0139 0139×××EC-903
HO2S1 (B2) P0152 0152 —××EC-863
HO2S1 (B2) P0153 0153×××EC-872
HO2S1 (B2) P0154 0154 —××EC-884
HO2S2 (B2) P0158 0158 —××EC-894
HO2S2 (B2) P0159 0159×××EC-903

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-705
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45FUEL SYS-LEAN-B1 P0171 0171 — —×EC-914
FUEL SYS-RICH-B1 P0172 0172 — —×EC-923
FUEL SYS-LEAN-B2 P0174 0174 — —×EC-914
FUEL SYS-RICH-B2 P0175 0175 — —×EC-923
FTT SENSOR P0181 0181 — —×EC-931
FTT SEN/CIRCUIT P0182 0182 — —×EC-937
FTT SEN/CIRCUIT P0183 0183 — —×EC-937
TP SEN 1/CIRC P0222 0222 — — —EC-942
TP SEN 1/CIRC P0223 0223 — — —EC-942
MULTI CYL MISFIRE P0300 0300 — —×EC-949
CYL 1 MISFIRE P0301 0301 — —×EC-949
CYL 2 MISFIRE P0302 0302 — —×EC-949
CYL 3 MISFIRE P0303 0303 — —×EC-949
CYL 4 MISFIRE P0304 0304 — —×EC-949
CYL 5 MISFIRE P0305 0305 — —×EC-949
CYL 6 MISFIRE P0306 0306 — —×EC-949
CYL 7 MISFIRE P0307 0307 — —×EC-949
CYL 8 MISFIRE P0308 0308 — —×EC-949
KNOCK SEN/CIRC-B1 P0327 0327 — —×EC-955
KNOCK SEN/CIRC-B1 P0328 0328 — —×EC-955
KNOCK SEN/CIRC-B2 P0332 0332 — —×EC-955
KNOCK SEN/CIRC-B2 P0333 0333 — —×EC-955
CKP SEN/CIRCUIT P0335 0335 — —×EC-960
CMP SEN/CIRC-B1 P0340 0340 — —×EC-966
TW CATALYST SYS-B1 P0420 0420×××EC-971
TW CATALYST SYS-B2 P0430 0430×××EC-971
EVAP PURG FLOW/MON P0441 0441×××EC-976
EVAP SMALL LEAK P0442 0442×××EC-981
PURG VOLUME CONT/V P0444 0444 — —×EC-990
PURG VOLUME CONT/V P0445 0445 — —×EC-990
VENT CONTROL VALVE P0447 0447 — —×EC-997
EVAP SYS PRES SEN P0451 0451 — —×EC-1004
EVAP SYS PRES SEN P0452 0452 — —×EC-1007
EVAP SYS PRES SEN P0453 0453 — —×EC-1014
EVAP GROSS LEAK P0455 0455 —××EC-1022
EVAP VERY SML LEAK P0456 0456
×*5××EC-1030
FUEL LEV SEN SLOSH P0460 0460 — —×EC-1040
FUEL LEVEL SENSOR P0461 0461 — —×EC-1042
FUEL LEVL SEN/CIRC P0462 0462 — —×EC-1044
FUEL LEVL SEN/CIRC P0463 0463 — —×EC-1044
VEH SPEED SEN/CIRC*6P0500 0500 — —×EC-1046
ISC SYSTEM P0506 0506 — —×EC-1048
Items
(CONSULT-II screen terms)DTC*
1
SRT codeTest value/
Test limit
(GST only)1st trip DTCReference
page CONSULT-II
GST*
2ECM*3

EC-708
[VK45DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2004 November 2004 FX35/FX45
For malfunctions in which 1st trip DTCs are displayed, refer to EC-704, "EMISSION-RELATED DIAGNOSTIC
INFORMATION ITEMS" . These items are required by legal regulations to continuously monitor the system/
component. In addition, the items monitored non-continuously are also displayed on CONSULT-II.
1st trip DTC is specified in Mode 7 of SAE J1979. 1st trip DTC detection occurs without lighting up the MIL and
therefore does not warn the driver of a malfunction. However, 1st trip DTC detection will not prevent the vehi-
cle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step II, refer to EC-727, "
WORK FLOW" . Then perform DTC Con-
firmation Procedure or Overall Function Check to try to duplicate the malfunction. If the malfunction is dupli-
cated, the item requires repair.
How to Read DTC and 1st Trip DTC
DTC and 1st trip DTC can be read by the following methods.
With CONSULT-II
With GST
CONSULT-II or GST (Generic Scan Tool) Examples: P0340, P1148, P1706, etc.
These DTCs are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)
No Tools
The number of blinks of the MIL in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0340, 1148, 1706, etc.
These DTCs are controlled by NISSAN.

1st trip DTC No. is the same as DTC No.

Output of a DTC indicates a malfunction. However, GST or the Diagnostic Test Mode II do not indi-
cate whether the malfunction is still occurring or has occurred in the past and has returned to nor-
mal. CONSULT-II can identify malfunction status as shown below. Therefore, using CONSULT-II (if
available) is recommended.
A sample of CONSULT-II display for DTC and 1st trip DTC is shown below. DTC or 1st trip DTC of a malfunc-
tion is displayed in “SELF-DIAGNOSTIC RESULTS” mode of CONSULT-II. Time data indicates how many
times the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be [0].
If a 1st trip DTC is stored in the ECM, the time data will be [1t].
FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME DATA
The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short term fuel trim, long term fuel trim, engine speed, vehicle speed, base fuel schedule and intake
air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II or
GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
details, see EC-764, "
Freeze Frame Data and 1st Trip Freeze Frame Data" .
Only one set of freeze frame data (either 1st trip freeze frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
PBIB0911E