2001 INFINITI QX4 Ac system

DIAGNOSTIC RESULT ITEM CHARTNBSC0019S01
Diagnostic item Service procedure
CRANKING VOLTAGE NORMAL Go to ªWORK FLOWº, SC-14.
CRANKING VOLTAGE LOW Go to ªWORK FLOWº, SC-14.
CHARGE BATTERYPerform the slow battery charging procedure. (Initial rate of charge is 10A for 12 hours.)
Perform battery test again with Battery/Starting/Charging system tester. Refer to SC-7.
REPLACE BATTERYBefore replacing battery, clean the battery cable clamps and battery posts. Perform bat-
tery test again with Battery/Starting/Charging system tester. Refer to SC-7. If second test
result is ªREPLACE BATTERYº, then do so. Perform battery test again to confirm repair.GI
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STARTING SYSTEM
Trouble Diagnoses with Battery/Starting/Charging System Tester (Cont'd)
SC-13

WORK FLOWNBSC0019S02
SEL411X
*1 SC-7
*2 SC-17*3 SC-15 *4 SC-17
STARTING SYSTEM
Trouble Diagnoses with Battery/Starting/Charging System Tester (Cont'd)
SC-14

DIAGNOSTIC PROCEDURE 1NBSC0019S03Check ªBº Terminal CircuitNBSC0019S0301
1 CHECK POWER SUPPLY FOR STARTER MOTOR ªBº 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. Check that the starter motor terminal 1 connection is clean and tight.
5. Check voltage between starter motor terminal 1 and ground using a digital circuit tester.
SEL412X
OK or NG
OK©GO TO 2.
NG©Check harness between the battery and the starter motor for open circuit.
2 CHECK BATTERY CABLE CONNECTION QUALITY (VOLTAGE DROP TEST)
1. Check voltage between starter motor terminal 1 and battery positive terminal using a digital circuit tester.
SEL413X
OK or NG
OK©GO TO 3.
NG©Check harness between the battery and the starter motor for poor continuity.
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STARTING SYSTEM
Trouble Diagnoses with Battery/Starting/Charging System Tester (Cont'd)
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3 CHECK STARTER MOTOR GROUND CIRCUIT (VOLTAGE DROP TEST)
1. Check voltage between starter motor case and battery negative terminal using a digital circuit tester.
SEL414X
OK or NG
OK©Starter motor ªBº terminal circuit is OK. Further inspection necessary. Refer to ªWORK
FLOWº, SC-14.
NG©Check the starter motor case and ground for poor continuity.
STARTING SYSTEM
Trouble Diagnoses with Battery/Starting/Charging System Tester (Cont'd)
SC-16

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

ConstructionNBSC0006
MEL949LB
MEL950L
Removal and InstallationNBSC0007
Pinion/Clutch CheckNBSC00081. Inspect pinion teeth.
IReplace pinion if teeth are worn or damaged. (Also check
condition of ring gear teeth.)
2. Inspect reduction gear teeth.
IReplace reduction gear if teeth are worn or damaged. (Also
check condition of armature shaft gear teeth.)
3. Check to see if pinion locks in one direction and rotates
smoothly in the opposite direction.
IIf it locks or rotates in both directions, or unusual resistance is
evident, replace.
STARTING SYSTEM
Construction
SC-18

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

Wiring Diagram Ð CHARGE ÐNBSC0010
MEL653L
CHARGING SYSTEM
Wiring Diagram Ð CHARGE Ð
SC-20