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Home >> Oldsmobile >> 2003 >> Bravada AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing - 4.2L >> Fuel Systems >> Fuel Injector Circuit Diagnosis >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform Diagnostic System Check - Engine Controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 4.2L BRAVADA, ENVOY, ENVOY XL, TRAILBLAZER & TRAILBLAZER EXT article. After performing Diagnostic System Check - Engine Controls, go to next step.
  2. Are any fuel injector DTCs set? If yes, diagnose affected DTC(s). See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 4.2L BRAVADA, ENVOY, ENVOY XL, TRAILBLAZER & TRAILBLAZER EXT article. If no, go to next step.
  3. Inspect the PCM 1 fuse. Is fuse open? If yes, go to next step. If no, go to step  6 .
  4. Turn ignition off. Disconnect fuel injectors multi-way harness connector. Using a test light connected to battery voltage, probe the ignition 1 voltage circuit of the fuel injector, fuse side. Does test light illuminate? If yes, go to step  9 . If no, go to next step.
  5. Turn ignition on, with engine off. Does test light illuminate? If yes, go to step  13 . If no, go to step  8 .
  6. Turn ignition off. Disconnect fuel injectors multi-way harness connector. Turn ignition on, with engine off. Using test light connected to ground, probe the ignition 1 voltage circuit of the fuel injector, fuse side. Does the test light illuminate? If yes, go to next step. If no, go to step  10 .
  7. Test for continuity between the ignition 1 voltage circuit terminal and a fuel injector terminal, at the multi-way harness connector, fuel injector side. Does the DVOM display OL? If yes, go to step  11 . If no, go to step  12 .
  8. Test fuel injector ignition 1 voltage circuit between the multi-way harness connector and fuel injectors for a short to ground. Did you find and correct the condition? If yes, go to step  14 . If no, problem is intermittent.
  9. Repair short to ground in the ignition 1 voltage circuit of the fuel injector. After repairs, go to step  14 .
  10. Repair open in the ignition 1 voltage circuit between the PCM 1 fuse and multi-way connector. After repairs, go to step  14 .
  11. Repair open or high resistance in the ignition 1 voltage circuit of the fuel injectors between the multi-way connector and splice. After repairs, go to step  14 .
  12. Repair poor connection at the multi-way harness connector. After repairs, go to step  14 .
  13. Repair short to a PCM ground in the ignition 1 voltage circuit of fuel injector. After repairs, go to next step.
  14. Operate system in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step  3 .
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