Initial Inspection and Diagnostic Overview

Diagnosis and Repair Workflow

Overall Sequence





Detailed Flow

NOTE:

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

1. DIAGNOSIS WITH MULTITASKING BATTERY DIAGNOSTIC STATION

Perform the starting system test with multitasking battery diagnostic station. For details and operating instructions, refer to diagnostic station instruction manual.

Test result
CRANKING NORMAL
GO TO 2
LOW VOLTAGE
GO TO 5
CHARGE BATTERY
ERROR! Unknown action!Perform the slow battery charging procedure. (Initial rate of charge is 10A for 12 hours.) Perform battery test again. Refer to diagnostic station instruction manual.
REPLACE BATTERY
ERROR! Unknown action!Before replacing battery, clean the battery cable clamps and battery posts. Perform battery test again. Refer to diagnostic station instruction manual. If second test result is "REPLACE BATTERY", then do so. Perform battery test again to confirm repair.

2. CRANKING CHECK

Check that the starter motor operates properly.

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 to Section 1A and 1D. 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 verify the cranking voltage is within specification.
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.

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 [B Terminal Circuit Check] B Terminal Circuit Check.

Is "B" terminal circuit normal?
YES
GO TO 8
NO
Repair as needed.

8. "S" CONNECTOR CIRCUIT INSPECTION

Check "S" connector circuit. Refer to [S Connector Circuit Check [QR25DE] S Connector Circuit Check ] (QR25DE) or [S Connector Circuit Check [VQ40DE] S Connector Circuit Check ] (VQ40DE).

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. Refer to [Starter Motor: Removal and Installation (QR25DE)] Service and Repair or [Starter Motor: Removal and Installation (VQ40DE)] Service and Repair.
NO
Perform further diagnosis of engine mechanical or powertrain mechanism. Refer to Section 1D, 5A and 5B. Once resolved, perform battery test again. Refer to diagnostic station instruction manual.