Infiniti Q45. Manual - part 791

STARTING SYSTEM

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STARTING SYSTEM 

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System Description 

NKS0016N

Power is supplied at all times

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through 50A fusible link (letter G , located in the fuse, fusible link and relay block)

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to ignition switch terminal 1.

With the ignition switch in the START position, power is supplied

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from ignition switch terminal 4

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to park/neutral position relay terminal 7.

Ground is supplied with the selector lever in the P or N position

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to A/T assembly terminal 9

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through park/neutral position relay terminals 1 and 2

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from grounds E24, E42 and E62.

Then park/neutral position switch is energized and power is supplied

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from park/neutral position relay terminal 6

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to starter motor harness connector terminal 1.

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.

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STARTING SYSTEM

Wiring Diagram — START — 

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TKWM1455E

STARTING SYSTEM

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Trouble Diagnosis with Battery/Starting/Charging System Tester

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NOTE:
To ensure a complete and thorough diagnosis, the battery, starter and alternator test segments must be done
as a set from start to finish.

1.

Turn off all loads on the vehicle electrical system.

2.

Perform battery test with Battery/Starting/Charging system
tester. Refer to 

SC-6, "Trouble Diagnosis with Battery/Starting/

Charging System Tester"

 .

3.

Press “ENTER” to begin the starting system test.

4.

Start the engine.

5.

Diagnostic result is displayed on the tester. Refer to 

SC-11,

"DIAGNOSTIC RESULT ITEM CHART"

 .

NOTE:

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If the starter performs normally but the engine does not start,
perform engine diagnosis.

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For intermittent “NO CRANK” or “NO STARTER OPERA-
TION” incidents, go to DIAGNOSTIC PROCEDURE 2.

DIAGNOSTIC RESULT ITEM CHART

SEL408X

SEL409X

SEL410X

Diagnostic item

Service procedure

CRANKING VOLTAGE NORMAL

Go to 

SC-12, "WORK FLOW"

 .

CRANKING VOLTAGE LOW

CHARGE BATTERY

Perform 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-6, "Trouble Diagnosis 

with Battery/Starting/Charging System Tester"

 .

REPLACE BATTERY

Before replacing battery, clean the battery cable clamps and battery posts. Perform battery test 
again with Battery/Starting/Charging system tester. Refer to 

SC-6, "Trouble Diagnosis with Bat-

tery/Starting/Charging System Tester"

 . If second test result is “REPLACE BATTERY”, then do so. 

Perform battery test again to confirm repair.

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STARTING SYSTEM

WORK FLOW

*1

SC-6, "Trouble Diagnosis with Bat-
tery/Starting/Charging System 
Tester"

*2

SC-14, "MINIMUM SPECIFICATION 
OF CRANKING VOLTAGE REFER-
ENCING COOLANT TEMPERA-
TURE"

*3

SC-13, "Check “B” Terminal Circuit"

*4

SC-14, "Check “S” Connector Cir-
cuit"

SKIB1369E