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Diagnostic Procedures

  1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK -- ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 3.4L MONTANA, SILHOUETTE & VENTURE article. After performing diagnostic system check, go to next step.
  2. Turn ignition on, with engine off. Remove the underhood fuse/relay block cover. Probe the following fuses with a test light that is connected to a good ground; INJ fuse, IGN 1 UH fuse, ELEK IGN fuse, TCC fuse and A/C CLU fuse. See Figure . Does the test light illuminate on at least one test point of each fuse? If yes, go to next step. If no, go to step  11 .
  3. Turn ignition off. Probe both test points of the A/C CLU fuse with a test light that is connected to a good ground. Does the test light illuminate on either test point of the fuse? If yes, go to next step. If no, go to step  36 .
  4. Turn ignition off. Remove ignition relay from the underhood fuse/relay block. Probe both test points of the 10-amp PCM/ABS fuse in the instrument panel fuse/relay block with a test light that is connected to a good ground. Does the test light illuminate on any of the fuse test points? If yes, go to step  8 . If no, go to next step.
  5. Test the ignition relay load circuit bus bar of the underhood fuse/relay block between the ignition relay and the fuses to the circuit components for a short to battery positive voltage. Did you find and correct the condition? If yes, go to step  35 . If no, go to next step.
  6. Turn ignition off. Remove the following fuses from the underhood fuse/relay block: INJ fuse, IGN 1 UH fuse, ELEK IGN fuse, TCC, fuse and A/C CLU fuse. Probe all these fuse terminals with a test light connected to a good ground. Does the test light illuminate at any of the fuse terminals? If yes, go to next step. If no, go to step  32 .
  7. Turn ignition off. Remove the A/C clutch relay from the underhood fuse/relay. Probe both fuse terminals of the A/C CLU fuse in the underhood fuse/relay block with a test light that is connected to a good ground. Does the test light illuminate on either fuse terminal? If yes, diagnose engine electrical system. If no, go to step  34 .
  8. Turn ignition off. Disconnect the ignition switch electrical connector. Connect a 20-amp fuse jumper wire from the battery positive voltage terminal at the ignition switch connector, to the corresponding terminal at the vehicle harness connector. Probe the ignition 1 voltage circuit at the ignition switch electrical connector with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to step  33 . If no, go to next step.
  9. Remove the following fuses from the instrument panel fuse block: DRL fuse, PCM/ABS fuse, and CAN VENT SOL fuse. Probe the ignition 1 voltage circuit of the ignition switch electrical connector that leads to the I/P junction block, with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to step  30 . If no, go to next step.
  10. Turn ignition off. Disconnect the electrical connector at the underhood fuse/relay block that contains the ignition 1 voltage circuit of the ignition relay. Probe the ignition 1 voltage circuit of the ignition relay at the underhood fuse/relay block vehicle harness electrical connector with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to step  31 . If no, go to step  35 .
  11. Turn ignition off. Probe both test points of the 40-amp IGN 1 fuse in the underhood fuse/relay block with a test light connected to a good ground. See Figure . Does the test light illuminate on both test points of the fuse? If yes, go to step  15 . If no, go to next step.
  12. Does the test light illuminate on one test point of the 40-amp IGN 1 fuse? If yes, go to next step. If no, go to step  21 .
  13. Test the battery positive voltage circuit between the underhood fuse/relay block and the ignition switch for a short to ground. Did you find and correct the condition? If yes, go to step  36 . If no, go to next step.
  14. Test the ignition 1 voltage circuit between the ignition switch and the 10-amp PCM/ABS fuse terminals in the instrument panel fuse block for a short to ground. Did you find and correct the condition? If yes, go to step  36 . If no, go to step  33 .
  15. Turn ignition on, with engine off. Probe both test points of the 10-amp PCM/ABS fuse with a test light that is connected to a good ground. Does the test light illuminate on both test point of the fuse? If yes, go to step  22 . If no, go to next step.
  16. Does the test light illuminate on one test point of the 10-amp PCM/ABS fuse? If yes, go to step  19 . If no, go to next step.
  17. Test the ignition 1 voltage circuit between the ignition switch and the PCM/ABS fuse for a high resistance or for an open. Did you find and correct the condition? If yes, go to step  36 . If no, go to next step.
  18. Test the battery positive voltage circuit between the underhood fuse/relay block and the ignition switch for a high resistance or for an open. Did you find and correct the condition? If yes, go to step  36 . If no, go to step  33 .
  19. Test the ignition 1 voltage circuit between the instrument panel fuse block and the underhood fuse/relay block for a short to ground. Did you find and correct the condition? If yes, go to step  36 . If no, go to next step.
  20. Test the underhood fuse/relay block, ignition 1 voltage bus bar circuit to the ignition relay for a short to ground. Did you find a condition? If yes, go to step  35 . If no, go to step  32 .
  21. Turn ignition off. Probe the mounting stud for the battery positive cable at the underhood fuse/relay block with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to step  35 . If no, diagnose engine electrical system.
  22. Turn ignition off. Remove the ignition relay with the J 43244, from the underhood fuse/relay block. Probe the battery positive voltage circuit of the ignition relay at the underhood fuse/relay block with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to next step. If no, go to step  35 .
  23. Turn ignition on, with engine off. Probe the ignition 1 voltage circuit of the ignition relay at the underhood fuse/relay block with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to step  25 . If no, go to next step.
  24. Test the ignition 1 voltage circuit between the instrument panel fuse block and the underhood fuse/relay block for a high resistance or for an open. Did you find and correct the condition? If yes, go to step  36 . If no, go to step  35 .
  25. Turn ignition on, with engine off. Probe the coil ground circuit of the ignition relay at the underhood fuse/relay block with a test light that is connected to battery voltage. Does the test light illuminate? If yes, go to step  27 . If no, go to next step.
  26. Turn ignition off. Disconnect the negative battery cable at the battery. Disconnect the underhood fuse/relay block electrical connector that contains the relay coil ground circuit. Test the coil ground circuit of the ignition relay at the underhood fuse/relay block electrical connector for a high resistance or for an open. Did you find and correct the condition? If yes, go to step  36 . If no, go to step  35 .
  27. Turn ignition off. Jumper the ignition relay battery positive voltage circuit and the ignition relay load circuit together at the underhood fuse/relay block with a 20-amp fused jumper wire. Probe the following fuses with a test light that is connected to a good ground: INJ fuse, IGN 1 UH fuse, ELEK IGN fuse, TCC fuse and A/C CLU fuse. Does the test light illuminate on at least one test point of each fuse? If yes, go to next step. If no, go to step  35 .
  28. Remove the A/C clutch relay from the underhood fuse/relay block. Probe the ignition 1 voltage circuit of the A/C clutch relay with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to next step. If no, go to step  35 .
  29. Test for an intermittent and for a poor connection at the underhood fuse/relay block, ignition relay connector location Did you find a condition? If yes, go to step  35 . If no, go to step  32 .
  30. Repair short to battery positive voltage in the ignition 1 voltage circuit between the ignition switch and instrument panel fuse block. After repairs, go to step  36 .
  31. Repair short to battery positive voltage in the ignition 1 voltage circuit between the instrument panel fuse block and underhood fuse/relay block electrical connector. After repairs, go to step  36 .
  32. Replace ignition relay. After replacing relay, go to step  36 .
  33. Replace ignition switch. After replacing ignition switch, go to  36 .
  34. Replace A/C clutch relay. After replacing relay, go to step  36 .
  35. Replace underhood fuse/relay block. After replacing fuse/relay block, go to next step.
  36. Replace any open fuses. Turn ignition off for 30 seconds. Attempt to start the engine. Does the engine start and run? If yes, go to next step. If no, go to NO-START DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES - 3.4L MONTANA, SILHOUETTE & VENTURE article.
  37. Using scan tool, clear DTCs. Operate the vehicle for 5 minutes. Does a DTC set during this ignition cycle? If yes, diagnose affected DTC(s). See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 3.4L MONTANA, SILHOUETTE & VENTURE article. If no DTCs are set, system is okay.
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