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Home >> Pontiac >> 2002 >> Firebird Formula, Automatic >> Repair and Diagnosis >> Electrical >> Charging Systems >> Diagnostic Tests >> DTC P1637: Output Driver Module Malfunction >> Diagnostic Procedure
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Diagnostic Procedure

  1. If diagnostic system check was not performed, perform ENGINE ELECTRICAL DIAGNOSTIC SYSTEM CHECK  under ON-VEHICLE TESTING. If diagnostic system check was performed, go to next step.
  2. Turn ignition switch to OFF position. Disconnect generator. Measure voltage between generator turn-on signal circuit and ground. Start engine. Using scan tool, command generator ON and OFF. If voltage change is 0-5.0 volt, problem is intermittent. Check wiring and connections. If voltage change is not 0.0-5.0 volt, go to next step.
  3. Test generator turn-on signal circuit for a high resistance or an open. If problem exists, repair circuit as necessary. After repair, go to step  6 . If problem does not exist, go to next step.
  4. Inspect Powertrain Control Module (PCM) harness connector for poor connections. If problem exists, repair as necessary. After repair, go to step  6 . If connections are okay, go to next step.
  5. Replace PCM. See REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. Program PCM. After repair, go to next step.
  6. Using scan tool, clear DTCs. Turn ignition switch to RUN position. Operate vehicle with conditions of running DTC. If DTC P1637 resets, repeat test beginning at step  2 . If DTC P1637 does not reset, system is okay.
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