LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2021 >> Q50 Pure, AWD >> Repair and Diagnosis (Single Page) >> Electrical >> Charging Systems >> Charging System (Diagnostics) >> Basic Inspection >> Charging System >> Diagnosis And Repair Work Flow >> Work Flow >> Detailed Flow
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Detailed Flow

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. PRELIMINARY INSPECTION 

    Perform the preliminary inspection. Refer to Work Procedure .

    GO TO 2.

  2. STOP POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM 

    Stop the operation of the power generation voltage variable control in either of the following procedures.

    • After selecting "ENGINE" of "SELECT SYSTEM" using CONSULT, set the DUTY value of "ALTERNATOR DUTY" to 0 % by selecting "ALTERNATOR DUTY" of "Active Test". Continue "Active Test" until the end of inspection. (When the DUTY value is 0 or 100 %, the normal power generation is performed according to the characteristic of the IC voltage regulator of the alternator.)
    • Turn the ignition switch OFF, and disconnect the battery current sensor connector. [However, DTC (P1550 - P1554) of the engine might remain. After finishing the inspection, connect the battery current sensor connector and erase the self-diagnosis results history of the engine using CONSULT.]

    GO TO 3.

  3. DIAGNOSIS WITH EXP-800 NI OR GR8-1200 NI 

    Perform the charging system test using Multitasking battery and electrical diagnostic station GR8-1200 NI or Battery and electrical diagnostic analyzer EXP-800 NI. Refer to the applicable Instruction Manual for proper testing procedures.

    Test result

    NO

    Charging system is normal and will also show "DIODE RIPPLE" test result.

    NO

    GO TO 4.

    LOW VOLTAGE

    GO TO 12.

    HIGH VOLTAGE

    GO TO 14.

    EXCESSIVE RIPPLE, OPEN PHASE, OPEN DIODE or SHORTED DIODE

    Replace the alternator. Perform "DIODE RIPPLE" test again using Multitasking battery and electrical diagnostic station GR8-1200 NI or Battery and electrical diagnostic analyzer EXP-800 NI to confirm repair.

  4. INSPECTION WITH CHARGE WARNING LAMP (IGNITION SWITCH IS ON) 

    Turn the ignition switch ON.

    Does the charge warning lamp illuminate?

    YES

    GO TO 6.

    NO

    GO TO 5.

  5. "L" TERMINAL CIRCUIT (OPEN) INSPECTION 

    Check "L" terminal circuit (open). Refer to Diagnosis Procedure .

    Is the "L" terminal circuit normal?

    YES

    Replace alternator. Refer to ALTERNATOR : Removal & Installation .

    NO

    Repair as needed.

  6. INSPECTION WITH CHARGE WARNING LAMP (IDLING) 

    Start the engine and run it at idle.

    Does the charge warning lamp turn OFF?

    YES

    GO TO 9.

    NO

    GO TO 7.

  7. "L" TERMINAL CIRCUIT (SHORT) INSPECTION 

    Check "L" terminal circuit (short). Refer to Diagnosis Procedure .

    Is the "L" terminal circuit normal?

    YES

    GO TO 8.

    NO

    Repair as needed.

  8. "S" TERMINAL CIRCUIT INSPECTION 

    Check "S" terminal circuit. Refer to Diagnosis Procedure .

    Is the "S" terminal circuit normal?

    YES

    GO TO 10.

    NO

    Repair as needed.

  9. INSPECTION WITH CHARGE WARNING LAMP (ENGINE AT 3, 000 RPM) 

    Increase and maintain the engine speed at 3, 000 RPM.

    Does the charge warning lamp remain off?

    YES

    GO TO 11.

    NO

    GO TO 10.

  10. INSPECTION OF ALTERNATOR PULLEY 

    Check alternator pulley. Refer to ALTERNATOR : Inspection .

    Is alternator pulley normal?

    YES

    Replace alternator. Refer to ALTERNATOR : Removal & Installation .

    NO

    Repair as needed.

  11. "B" TERMINAL CIRCUIT INSPECTION 

    Check "B" terminal circuit. Refer to Diagnosis Procedure .

    Is "B" terminal circuit normal?

    YES

    Replace alternator. Refer to ALTERNATOR : Removal & Installation .

    NO

    Repair as needed.

  12. "B" TERMINAL CIRCUIT INSPECTION 

    Check "B" terminal circuit. Refer to Diagnosis Procedure .

    Is "B" terminal circuit normal?

    YES

    GO TO 13.

    NO

    Repair as needed.

  13. INSPECTION OF ALTERNATOR PULLEY 

    Check alternator pulley. Refer to ALTERNATOR : Inspection .

    Is alternator pulley normal?

    YES

    Replace alternator. Refer to ALTERNATOR : Removal & Installation .

    NO

    Repair as needed.

  14. "S" TERMINAL CIRCUIT INSPECTION 

    Check "S" terminal circuit. Refer to Diagnosis Procedure .

    Is the "S" terminal circuit normal?

    YES

    Replace alternator. Refer to ALTERNATOR : Removal & Installation .

    NO

    Repair as needed.