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HOMESERVICE MANUALSHONDA2002CIVIC SIREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 59 (CHARGING SYSTEM)ALTERNATOR AND REGULATOR CIRCUIT TROUBLESHOOTING
2002 Honda Civic Si

Alternator and Regulator Circuit Troubleshooting

2002 Honda Civic SiSECTION Alternator and Regulator Circuit Troubleshooting
WARNING: This page is about a different car, the 2006 Acura MDX, 2005 Acura MDX, 2004 Acura MDX, and 2003 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.
  1. Make sure the battery connections are good and the battery is sufficiently charged.
  2. Connect a VAT-40 (or equivalent tester), and turn the selector switch to position 1 (starting).
    Fig 1: Connecting VAT-40 And Turning Selector Switch To Position 1
    G03639176Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. Start the engine. Hold the engine at 3,000 rpm, without load and with the shift lever in P or N until the radiator fan comes on, then let it idle.
  4. Raise the engine speed to 2,000 rpm, and hold it there.

    Is the voltage over 15.1 V? 

    1. YES  - Replace the alternator (see ALTERNATOR REMOVAL AND INSTALLATION  ) or rear housing assembly (see ALTERNATOR OVERHAUL  ).
    2. NO  - Go to step 5.
  5. Release the accelerator pedal, and let the engine idle.
  6. Make sure the all accessories are turned off. Turn the selector switch to position 2 (charging).
  7. Remove the inductive pickup, and zero the ammeter.
  8. Place the inductive pickup over the B terminal wire of the alternator so the arrow points away from the alternator.
  9. Raise the engine speed to 2,000 rpm, and hold it there.

    Is the voltage less than 13.5 V? 

    1. YES  - Go to alternator control circuit troubleshooting (see ALTERNATOR CONTROL CIRCUIT TROUBLESHOOTING  ).
    2. NO  - Go to step 10.
  10. Apply a load with the VAT-40 until the battery voltage drops within 12-13.5 V.

    Is the amperage 87.5 A or more? 

    1. YES  - The charging system is OK.
    2. NO  - Replace the alternator (see ALTERNATOR REMOVAL AND INSTALLATION  ) or repair the alternator (see ALTERNATOR OVERHAUL  ).
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.