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Except 5.7L

  1. Turn ignition on, with engine off. If charging light illuminates, go to next step. If charging light does not illuminate, go to step  3.
  2. Start engine. If charging light does not go out, go to step  4. If charging light goes out, go to step  20.
  3. Turn ignition off. Disconnect generator harness connectors. Turn ignition on, with engine off. If charging light illuminates, go to step  5. If charging light does not illuminate, go to step  6.
  4. Turn ignition off. Install scan tool. Turn ignition on. Ensure all accessories are off. Using scan tool, observe generator voltage. If scan tool displays battery voltage or less, go to step  7. If scan tool displays greater than battery voltage, go to step  8.
  5. Using a test light connected to ground, probe charging light signal circuit at generator harness connector. If test light illuminates, go to step  9. If test light does not illuminate, go to step  10.
  6. Turn ignition off. Replace or repair instrument cluster and/or charging light bulb as necessary. After repairs, go to step  20.
  7. Using scan tool, check generator PWM value. If scan tool displays greater than 5 percent, go to step  6. If scan tool does not display greater than 5 percent, go to step  11.
  8. Turn ignition off. Disconnect generator harness connectors. Turn ignition on, with engine off. Using a test light connected to battery voltage, probe charging light signal circuit at generator harness connector. If test light illuminates, go to step  12. If test light does not illuminate, go to step  13.
  9. Locate and repair short to voltage in charging light control signal circuit. After repairs, go to step  20.
  10. Replace generator. After repairs, go to step  20.
  11. Turn ignition off. Disconnect generator harness connectors. Turn ignition on, leaving engine off. Using a test light connected to battery voltage, probe generator field circuit at generator harness connector. If test light illuminates, go to step  14. If test light does not illuminate, go to step  15.
  12. Locate and repair short to ground in charging light control signal circuit. After repairs, go to step  20.
  13. Using DVOM connected to ground, measure voltage at charging light signal circuit of generator harness connector. If voltage is greater than 4.5 volts, go to step  16. If voltage is less than 4.5 volts, go to step  17.
  14. Locate and repair short to ground in generator field circuit. After repairs, go to step  20.
  15. Locate and repair poor connection and/or open in generator field circuit. After repairs, go to step  20.
  16. Using DVOM connected to ground, measure voltage at battery voltage supply circuit of generator harness connector. If battery voltage exist, go to step  10. If battery voltage does not exist, go to step  18.
  17. Locate and repair poor connection and/or open in charging light signal circuit of generator harness connector. After repairs, go to step  20.
  18. Locate and repair poor connection and/or open in battery voltage supply circuit of generator harness connector. After repairs, go to step  20.
  19. Check for poor connections at PCM. If connections are okay, replace PCM. After repairs, go to next step.
  20. Operate vehicle under condition under which original symptom was noted. If system does not operate properly, go to step  1.
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