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Home >> Pontiac >> 2000 >> Firebird Formula, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - 5.7L >> Diagnostic Tests >> DTC P0200: Injector Control Circuit >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD system check, go to next step.
  2. Start engine. Using scan tool, monitor all the MISFIRE CURRENT COUNTERS in MISFIRE DATA LIST. If any of the misfire counters are incrementing, go to step  4. If misfire counters are not incrementing, go to next step.
  3. Monitor MISFIRE HISTORY COUNTERS. If counters indicate a number other than 0.0 counts, go to step  18. If counters does not indicate a number other than 0.0 counts, see DIAGNOSTIC AIDS .
  4. Check injector fuses. If fuses are okay, go to next step. If fuses are not okay, go to step  8.
  5. Turn ignition off. Disconnect injector harness connector from injector indicating an incrementing misfire counter. Turn ignition on, with engine off. Using a test light connected to ground, probe injector harness ignition feed circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step  10.
  6. Turn ignition off. Connect an Injector Test Light (J-34730-2C) to harness connector of affected injector. Operate engine at idle. If injector test light blinks, go to next step. If injector test light does not blink, go to step  11.
  7. Check injector harness terminals for poor connections. Repair as necessary. After repairs, go to step  19. If connections are okay, go to step  9.
  8. Turn ignition off. Disconnect the 4 injector harness connectors related to the fuse that was open. Using a test light connected to battery voltage, probe injector feed circuits of one of the injector harnesses that are disconnected. If test light illuminates, go to step  13. If test light does not illuminate, go to next step.
  9. Perform fuel injector coil test. See FUEL SYSTEM in appropriate SYSTEM & COMPONENT TESTING article. If test isolated an injector condition, go to step  15. If test did not isolate an injector condition, go to step  14.
  10. Repair injector ignition feed circuit to affected injector. After repairs, go to step  19.
  11. Turn ignition off. Disconnect PCM harness connector. Check injector control circuit for open, short to ground or short to voltage. If injector control circuit is open or shorted, go to next step. If injector control circuit is okay, go to step  16.
  12. Repair injector control circuit. After repairs, go to step  19.
  13. Repair grounded ignition feed circuit to injectors. Replace fuse. After repairs, go to step  19.
  14. Repair intermittent short to ground in ignition feed circuit to injectors. After repairs, go to step  19.
  15. Replace faulty injector(s). After replacing injector, go to step  19.
  16. Check for poor connections at PCM. Repair as necessary. After repairs, go to step  19. If connections are okay, go to next step.
  17. Replace PCM. Program replacement PCM using required equipment. After system is okay, go to next step.
  18. Check for poor connections at injector and PCM. Check for intermittent short to ground or open in circuit. Repair as necessary. After repairs, go to next step. If connections are okay, see DIAGNOSTIC AIDS .
  19. Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step  2.
  20. Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test.
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