Infiniti G37 Coupe. Manual - part 1283

DIAGNOSIS AND REPAIR WORKFLOW

STR-3

< BASIC INSPECTION >

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

1.

DIAGNOSIS WITH STARTING/CHARGING SYSTEM TESTER

Perform the starting system test with Starting/Charging System Tester (SST: J-44373). For details and operat-
ing instructions, refer to Technical Service Bulletin.

Test result

CRANKING VOLTAGE NORMAL>>GO TO 2.
CRANKING VOLTAGE LOW>>GO TO 5.
CHARGE BATTERY>>Perform  the  slow  battery charging procedure. (Initial rate of charge is 10A for 12

hours.) Perform battery test again. Refer to Technical Service Bulletin. 

REPLACE BATTERY>>Before replacing battery, clean the battery cable clamps and battery posts. Perform

battery test again. Refer to Technical Service Bulletin. If second test result is “REPLACE BAT-
TERY”, then do so. Perform battery test again to confirm repair.

2.

CRANKING CHECK

Check that the starter motor operates correctly.

Does the engine crank normally?

YES

>> GO TO 3.

NO

>> GO TO 4.

3.

ENGINE START CHECK

Check that the engine starts.

Does the engine start?

YES

>> Starter motor is OK. INSPECTION END

NO

>> Perform further diagnosis of engine mechanical or engine control system. Refer EM and EC sec-

tions. Once resolved, perform battery test again.

4.

STARTER MOTOR ACTIVATION

Check that the starter motor operates.

Does the starter motor turn?

YES

>> Check ring gear and starter motor drive pinion. Once resolved, perform battery test again.

NO

>> GO TO 7.

5.

COMPARISON BETWEEN ENGINE COOLANT AND CRANKING VOLTAGE

Compare the engine coolant temperature and the cranking voltage with the specifications.

Minimum Specification of Cranking Voltage Referencing Coolant Temperature

Is the voltage less than the specified value?

YES

>> GO TO 7.

NO

>> GO TO 6.

6.

STARTER OPERATION

Check the starter operation status.

Does the starter motor turn smoothly?

YES

>> Starter motor is OK. INSPECTION END

NO

>> GO TO 7.

7.

“B” TERMINAL CIRCUIT INSPECTION

Check “B” terminal circuit. Refer to 

STR-7, "Diagnosis Procedure"

.

Is “B” terminal circuit normal?

Engine coolant temperature [

°

C (

°

F)]

Voltage [V]

−

30 to 

−

20 (

−

22 to 

−

4)

8.6

−

19 to 

−

10 (

−

2 to 14)

9.1

−

9 to 0 (16 to 32)

9.5

More than 1 (More than 34)

9.9

STR-4

< BASIC INSPECTION >

DIAGNOSIS AND REPAIR WORKFLOW

YES

>> GO TO 8.

NO

>> Repair as needed.

8.

“S” CONNECTOR CIRCUIT INSPECTION

Check “S” connector circuit. Refer to 

STR-8, "Diagnosis Procedure"

.

Is “S” connector circuit normal?

YES

>> GO TO 9.

NO

>> Repair as needed.

9.

ENGINE ROTATION STATUS

Check that the engine can be rotated by hand.

Does the engine turn freely by hand?

YES

>> Replace starter motor.

NO

>> Perform further diagnosis of engine mechanical or powertrain mechanism. Refer to EM, TM or CL

sections. Once resolved, perform battery test again. Refer to Technical Service Bulletin. 

STARTING SYSTEM

STR-5

< FUNCTION DIAGNOSIS >

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FUNCTION DIAGNOSIS

STARTING SYSTEM

System Diagram

INFOID:0000000001665977

System Description

INFOID:0000000001665978

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. 

JSBIA0006GB

STR-6

< FUNCTION DIAGNOSIS >

STARTING SYSTEM

Component Parts Location

INFOID:0000000001665979

Component Description

INFOID:0000000001665980

1.

Starter motor

2.

BCM

3.

IPDM E/R

4.

Battery

5.

TCM

6.

Clutch interlock switch

A.

Engine

B.

Dash side lower (passenger side)

C.

Engine room dash panel (RH)

D.

Inside of A/T (built into A/T)

E.

Clutch pedal

JSBIA0005ZZ

Component part

Description

TCM

TCM supplies power to the starter relay and starter control relay 
inside IPDM E/R when the selector lever is shifted to the P or N 
position.

Clutch interlock switch

The switch turns ON and electric power is supplied to the starter 
relay and starter control relay inside IPDM E/R when the clutch 
pedal is depressed.

BCM

BCM controls the starter relay inside IPDM E/R.

IPDM E/R

CPU inside IPDM E/R controls the starter control relay.

Starter motor

The starter motor plunger closes and the motor is supplied with 
battery power, which in turn cranks the engine, when the “S” ter-
minal is supplied with electric power.