LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Pontiac >> 2003 >> Sunfire Automatic >> Repair and Diagnosis >> Electrical >> Charging Systems >> System Tests >> Test A: Charging System Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test A: Charging System Test

  1. If diagnostic system check was not performed, go to ENGINE ELECTRICAL DIAGNOSTIC SYSTEM CHECK  under ON-VEHICLE TESTING. If diagnostic system check was performed, go to next step.
  2. The battery must be above a 70 percent state of charge. If battery inspection test was performed, go to next step. If battery inspection test was not performed, see BATTERY TESTING & INSPECTION  under ON-VEHICLE TESTING.
  3. Install scan tool. Start engine. With scan tool, command the GEN-L Terminal OFF and ON. Observe the IGNITION 1 SIGNAL parameter. The voltage should change with each command. If voltage changes with each command, go to next step. If voltage does not change with each command, go to step  8.
  4. Turn ON the following accessories:
    • Headlights - high beams.
    • A/C on, MAX.
    • Blower fan - ON high.
    • Heated seats (if equipped).
    With a scan tool, observe the IGNITION 1 SIGNAL parameter in the engine data list. Increase engine speed to 2500 RPM. Voltage should 12.0-15.5 volts. If voltage is as specified, go to next step. If voltage is not as specified, go to step  6.
  5. Turn OFF all accessories. Turn OFF the ignition. Connect a carbon pile tester to the vehicle. Connect an inductive ammeter probe to the output circuit of the generator. Start engine. With scan tool, command the GEN-L Terminal ON. Increase engine speed to 2500 RPM. Adjust the carbon pile as necessary in order to obtain maximum current output of greater than or equal to specification. See GENERATOR SPECIFICATIONS . If amperage is as specified, system is okay. If amperage is not as specified, go to step  7.
  6. If the voltage measured is greater than 15.5 volts, go to step  12. If the voltage measured is not greater than 15.5 volts, go to next step.
  7. Leave the vehicle accessories ON or maintain load test value. Maintain engine speed at 2500 RPM. Measure the voltage between the generator output terminal and the generator metal housing. If B+ voltage is measured, go to step  14. If B+ voltage is not measured, go to step  9.
  8. Turn ignition switch to OFF position. Disconnect generator harness connector. Turn ON the ignition, with the engine OFF. Measure voltage between ground and generator harness connector terminal "B" (Red wire). Using scan tool, command GEN-L Terminal ON and OFF. Voltage should be zero volts with generator commanded OFF, and greater than 4.7 volts with generator commanded ON. If voltage is as specified, go to step  14. If voltage is not as specified, go to step  11.
  9. Maintain engine speed at 2500 RPM and continue to operate generator at load test value. Using a DVOM, measure voltage drop between battery negative terminal and the metal housing of the generator. If voltage drop is 0.5 volt or less, go to next step. If voltage drop is greater than 0.5 volt, go to step  15.
  10. Maintain engine speed at 2500 RPM and continue to operate generator at load test value. Using a DVOM, measure the voltage drop from the output terminal of the generator to the positive terminal on the battery. If voltage drop is 0.5 volt or less, go to step  14. If voltage drop is greater than 0.5 volt, go to step  16.
  11. Test Red wire for a short or open between generator harness connector terminal "B" and PCM harness connector C2 terminal No. 50. See WIRING DIAGRAMS . If problem does not exist, go to step  13. If problem exists, repair as necessary. After repair, go to step After repair, go to step  19.
  12. Test Orange wire (if equipped) for a high resistance or open between generator harness connector terminal "D" and 10-amp fuse. If problem does not exist, go to step  14. If problem exists, repair as necessary. After repair, go to step  19.
  13. Inspect PCM harness connector for poor connections. If problem does not exist, go to step  17. If problem exists, repair as necessary. After repair, go to step  19.
  14. Inspect generator harness connector for poor connections. If problem exists, repair as necessary. After repair, go to step  19. If problem does not exist, go to step  18.
  15. Repair high resistance or open in ground circuit of generator. See WIRING DIAGRAMS . After repair, go to step  19.
  16. Test B+ circuit for a high resistance or open. If problem exists, repair as necessary. After repair, go to step  19.
  17. Replace PCM. After replacement, reprogram PCM. See appropriate REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. After repair, go to step  19.
  18. Replace generator. See GENERATOR  under REMOVAL & INSTALLATION. After repair, go to next step.
  19. Operate system to verify repair. If system is not operating correctly, repeat test beginning at step  2.
  1. If diagnostic system check was not performed, go to ENGINE ELECTRICAL DIAGNOSTIC SYSTEM CHECK  under ON-VEHICLE TESTING. If diagnostic system check was performed, go to next step.
  2. Start engine and observe charge indicator on Instrument Panel Cluster (IPC), or charge message in Driver Information Center (DIC). If charge indicator light illuminates, or DIC displays a charging system message, go to next step. If charge indicator light does not illuminate or no message is present, problem is intermittent. Check wiring and connections.
    3. NOTE: Green POWER light on tester should remain illuminated while tester is being used.
  3. Turn ignition switch to LOCK position. Using CS Electronic Generator Tester (J-41450-B), connect Red lead to generator output terminal and Black lead to metal generator housing. If Green POWER light illuminates, go to step  6. If Green POWER light does not illuminate, go to next step.
  4. Measure voltage between output terminal of generator and generator housing. If battery voltage is present, go to step  14. If battery voltage is not present, go to next step.
  5. Measure voltage from generator output terminal to negative battery terminal. If battery voltage is present, go to step  12. If battery voltage is not present, go to step  11.
    6. CAUTION: Make sure load is completely turned off before connecting or disconnecting carbon pile load tester to battery.
  6. Connect carbon pile tester to battery. Connect inductive ammeter to output circuit of generator. Disconnect generator harness connector. Locate matching harness connector on Electronic Generator Tester and connect it to generator. If Red DIAGNOSTIC light on tester illuminates, go to next step. If Red DIAGNOSTIC light does not illuminate, go to step  13.
  7. Start engine and allow to idle for 30 seconds. Increase engine speed to 2500 RPM. If Red DIAGNOSTIC light does not illuminate, go to next step. If Red DIAGNOSTIC light illuminates, go to step  15.
  8. Maintain engine speed at 2500 RPM. Turn on load of carbon pile tester and increase load until generator output is greater than or equal to generator load test value. See GENERATOR SPECIFICATIONS . If Red DIAGNOSTIC light illuminates, go to step  15. If Red DIAGNOSTIC light does not illuminate, go to next step.
  9. Maintain engine speed at 2500 RPM and continue to operate generator at test load value. Measure voltage drop between generator output terminal and positive battery terminal. If voltage drop is greater than 0.5 volt, go to step  11. If voltage drop is less than 0.5 volt, go to next step.
  10. Maintain engine speed at 2500 RPM and continue to operate generator at test load value. Measure voltage drop between generator metal housing and negative battery terminal. If voltage drop is greater than 0.5 volt, go to step  12. If voltage drop is less than 0.5 volt, go to step  16.
  11. Repair high resistance or open in generator output circuit between generator output terminal and positive battery terminal. See WIRING DIAGRAMS . Repair circuit as necessary, then go to step  16.
  12. Repair high resistance or open in ground circuit of generator. See WIRING DIAGRAMS . Repair circuit as necessary, then go to step  16.
  13. Disconnect generator harness connector from generator, but leave alligator clips connected so Green POWER light remains on. Connect a jumper wire with an in-line 100 ohm resistor between harness connector terminal "B" and a good ground. See Fig 1. If Red DIAGNOSTIC light illuminates, go to step  15. If Red DIAGNOSTIC light does not illuminate, go to next step.
  14. There is a problem with CS Electronic Generator Tester (J-41450-B). Refer to manufacturer's instructions, how to test the generator tester for proper operation. If tester has been repaired or replaced, go to step  3.
  15. Replace generator. See GENERATOR  under REMOVAL & INSTALLATION. Once replacement is complete, go to next step.
  16. Retest system to verify repair. If condition was corrected, system is okay. If condition was not corrected, go to step  2.
Fig 1: Identifying Generator Harness Connector Terminals
G00060587Courtesy of GENERAL MOTORS CORP.
scientia non olet · About LEMON Manuals