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Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 1.8L VIBE article.
  2. Test for an open EFI fuse. Was an open fuse found? If yes, go to step  10 . If no, go to next step.
  3. Turn ignition switch to RUN position, engine OFF. Remove and reinstall the EFI relay several times while listening for a clicking sound from the relay. Did the EFI relay click when being reinstalled into the fuse block? If yes, go to next step. If no, go to step  5 .
  4. Turn ignition switch to OFF position. Remove EFI relay from the underhood fuse block. Turn ignition switch to RUN position, engine OFF. Probe the fuse block side of terminal No. 5 using a test light connected to ground. See Figure . Does the test light illuminate? If yes, go to step  11 . If no, go to step  7 .
  5. Probe EFI relay terminal No. 1 on the fuse block side using a test light connected to ground. See Figure . Does the test light illuminate? If yes, go to next step. If no, go to step  8 .
  6. Turn ignition switch to OFF position. Probe EFI relay terminal No. 2 of on the fuse block side using a test light connected to battery voltage. Does the test light illuminate? If yes, go to step  12 . If no, go to step  9 .
  7. Repair the open or poor connection in the ignition positive voltage circuit between the EFI fuse and the EFI relay. After repair, go to step  14 .
  8. Check for an open, a poor connection, or a short to ground in the EFI relay control circuit between the EFI relay and the PCM. Repair as necessary. Did you find and correct the condition? If yes, go to step  14 . If no, go to step  13 .
  9. Repair the open in the ground circuit between the EFI relay and ground point G103. After repair, go to step  14 .
  10. Repair the short to ground in the EFI fuse circuit. After repair, go to step  14 .
  11. Check EFI relay circuit for an open or a poor connection, from terminal No. 3 to the component or system that is not receiving voltage. Repair as necessary. Did you find and correct a wiring fault? If yes, go to step  14 . If no, go to next step.
  12. Replace the EFI relay. After repair, go to step  14 .
  13. Replace PCM. See POWERTRAIN CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION - VIBE article. After repair, go to next step.
  14. Operate the vehicle within the conditions under which the original concern was noted. Does the system operate properly with no DTCs? If yes, system is okay at this time. If no, see DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - VIBE article.
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