2001 INFINITI QX4 fuse box

5. Turn ignition switch ªOFFº.
SMA861C
6. Loosen fuel hose clamps.
7. Replace fuel filter.
IBe careful not to spill fuel over engine compartment. Place
a shop towel to absorb fuel.
IUse a high-pressure type fuel filter. Do not use a synthetic
resinous fuel filter.
IWhen tightening fuel hose clamps, refer to ªChecking Fuel
Linesº.
SMA869C
WITHOUT CONSULT-IINBMA0013S021. Remove fuel pump fuse located in fuse box.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch ªOFFº and install fuel pump fuse.
SMA861C
5. Loosen fuel hose clamps.
6. Replace fuel filter.
IBe careful not to spill fuel over engine compartment. Place
a shop towel to absorb fuel.
IUse a high-pressure type fuel filter. Do not use a synthetic
resinous fuel filter.
IWhen tightening fuel hose clamps, refer to ªChecking Fuel
Linesº.
SMA095D
Changing Air Cleaner FilterNBMA0014VISCOUS PAPER TYPENBMA0014S01The viscous paper type filter does not need cleaning between
replacement intervals.
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ENGINE MAINTENANCE
Changing Fuel Filter (Cont'd)
MA-17

System DescriptionNBSC0004Power is supplied at all times
Ito ignition switch terminal 1
Ithrough 40A fusible link (lettere, located in the fuse and fusible link box).
With the ignition switch in the ON or START position, power is supplied through 10A fuse [No. 18, located in
the fuse block (J/B)].
Ito park/neutral position relay terminal 1.
Also, with the ignition switch in the START position, power is supplied
Ifrom ignition switch terminal 5
Ito park/neutral position relay terminal 6.
With the selector lever in the P or N position, ground is supplied
Ito park/neutral position relay terminal 2 through the park/neutral position switch.
Then park/neutral position relay is energized and power is supplied
Ifrom park/neutral position relay terminal 7
Ito terminal 2 of the starter motor windings.
The starter motor plunger closes and provides a closed circuit between the battery and starter motor. The
starter motor is grounded to the engine block. With power and ground supplied, cranking occurs and the engine
starts.
STARTING SYSTEM
System Description
SC-10

DIAGNOSTIC PROCEDURE 2=NBSC0019S04Check ªSº Terminal CircuitNBSC0019S0401
1 CHECK POWER SUPPLY FOR STARTER MOTOR ªSº TERMINAL
1. Remove the fuel pump fuse.
2. Crank or start the engine (where possible) until the fuel pressure is released.
3. Turn the ignition OFF.
4. Disconnect starter motor terminal 2 connector.
5. Check voltage between starter motor terminal 2 and ground using a digital circuit tester.
SEL415X
OK or NG
OK©GO TO 2.
NG©Check the following.
I40A fusible link (lettere, located in fuse and fusible link box)
IPark/neutral position relay
IHarness for open or short
2 CHECK ªSº TERMINAL CONNECTION QUALITY (VOLTAGE DROP TEST)
1. Connect starter motor terminal 2 connector.
2. Check voltage between starter motor terminal 2 and battery positive terminal using a digital tester.
SEL416X
OK or NG
OK©Starter motor ªSº terminal circuit is OK. Further inspection necessary. Refer to ªWORK
FLOWº, SC-14.
NG©Check harness between the battery and the starter motor ªSº terminal for poor continuity.
MINIMUM SPECIFICATION OF CRANKING VOLTAGE
REFERENCING COOLANT TEMPERATURE
NBSC0019S05
Engine coolant temperature Voltage V
þ30ÉC to þ20ÉC (þ22ÉF to þ4ÉF) 8.6
þ19ÉC to þ10ÉC (þ2ÉF to 14ÉF) 9.1
þ9ÉC to 0ÉC (16ÉF to 32ÉF) 9.5
More than 1ÉC (More than 34ÉF) 9.9
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STARTING SYSTEM
Trouble Diagnoses with Battery/Starting/Charging System Tester (Cont'd)
SC-17

System DescriptionNBSC0009The alternator provides DC voltage to operate the vehicle's electrical system and to keep the battery charged.
The voltage output is controlled by the IC regulator.
Power is supplied at all times to alternator terminal S through:
I120A fusible link (lettera, located in the fuse and fusible link box), and
I7.5A fuse (No. 65, located in the fuse and fusible link box).
Terminal B supplies power to charge the battery and operate the vehicle's electrical system. Output voltage
is controlled by the IC regulator at terminal S detecting the input voltage. The charging circuit is protected by
the 120A fusible link.
Terminal E of the alternator supplies ground through body ground E101.
With the ignition switch in the ON or START position, power is supplied
Ithrough 10A fuse [No. 8, located in the fuse block (J/B)]
Ito combination meter terminal 12 for the charge warning lamp.
Ground is supplied to terminal 43 of the combination meter through terminal L of the alternator. With power
and ground supplied, the charge warning lamp will illuminate. When the alternator is providing sufficient volt-
age with the engine running, the ground is opened and the charge warning lamp will go off.
If the charge warning lamp illuminates with the engine running, a fault is indicated.GI
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CHARGING SYSTEM
System Description
SC-19

DIAGNOSTIC PROCEDURE 2=NBSC0020S04Check ªBº Terminal CircuitNBSC0020S0401
1 CHECK ªBº TERMINAL CONNECTION
Check to see if ªBº terminal is clean and tight.
OK or NG
OK©GO TO 2. Confirm repair by performing complete Battery/Starting/Charging system test.
NG©Repair ªBº terminal connection.
2 CHECK ALTERNATOR ªBº TERMINAL CIRCUIT
Check voltage between alternator terminal B and ground using a digital circuit tester.
SEL425X
OK or NG
OK©GO TO 3.
NG©Check the following.
I120A fusible link (lettera, located in fuse and fusible link box)
IHarness for open or short between alternator and fusible link
3 CHECK ªBº TERMINAL CONNECTION QUALITY (VOLTAGE DROP TEST)
Check voltage between alternator terminal B and battery positive terminal using a digital tester.
SEL426X
OK or NG
OK©Replace the alternator. Confirm repair by performing complete Battery/Starting/Charging
system test.
NG©Check harness between the battery and the alternator for poor continuity.
CHARGING SYSTEM
Trouble Diagnoses with Battery/Starting/Charging System Tester (Cont'd)
SC-26

DIAGNOSTIC PROCEDURE 3=NBSC0020S05Check ªSº Terminal CircuitNBSC0020S0501
1 CHECK ªSº TERMINAL CONNECTION
Check to see if ªSº terminal is clean and tight.
OK or NG
OK©GO TO 2.
NG©Repair ªSº terminal connection. Confirm repair by performing complete Battery/Starting/
Charging system test.
2 CHECK ALTERNATOR ªSº TERMINAL CIRCUIT
Check voltage between alternator terminal 2 and ground using a digital circuit tester.
SEL427X
OK or NG
OK©GO TO 3.
NG©Check the following.
I7.5A fuse (No. 65, located in fuse and fusible link box)
IHarness for open or short between alternator and fuse
3 CHECK ªSº TERMINAL CONNECTION QUALITY (VOLTAGE DROP TEST)
Check voltage between alternator terminal 2 and battery positive terminal using a digital tester.
SEL428X
OK or NG
OK©Replace the alternator. Confirm repair by performing complete Battery/Starting/Charging
system test.
NG©Check harness between the battery and the alternator for poor continuity.
MALFUNCTION INDICATORNBSC0020S06The IC regulator warning function activates to illuminate
ªCHARGEº warning lamp, if any of the following symptoms occur
while alternator is operating:
IExcessive voltage is produced.
INo voltage is produced.
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CHARGING SYSTEM
Trouble Diagnoses with Battery/Starting/Charging System Tester (Cont'd)
SC-27