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Home >> Pontiac >> 2002 >> Aztek FWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Ignition System >> Ignition Relay Diagnosis (8.1L) >> Diagnostic Procedure
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Diagnostic Procedure

  1. Perform Diagnostic System Check - Engine Controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 8.1L "C", "G" & "K" SERIES TRUCKS article. After performing Diagnostic System Check - Engine Controls, go to next step.
  2. Turn OFF the ignition. Remove underhood fuse block cover. Remove ignition relay with Relay Puller Pliers (J 43244). Probe battery positive voltage circuit for ignition relay at underhood fuse block with test light connected to ground. Does test light illuminate? If yes, go to next step. if no, go to step  10.
  3. Turn ON the ignition, with the engine OFF. Probe Ignition 1 voltage circuit for ignition relay at underhood fuse block with test light connected to ground. Does test light illuminate? If yes, go to next step. If no, go to step  6.
  4. Turn ON the ignition, with the engine OFF. Probe coil ground circuit for ignition relay at underhood fuse block with test light connected to battery voltage. Does test light illuminate? If yes, go to next step. If no, go to step  7.
    5. NOTE: At least one test point of each fuse must illuminate test light.
  5. Turn OFF the ignition. Jumper IGN relay battery positive voltage circuit and IGN relay load circuit together using fused jumper wire. Probe ECM I, INJ A and INJ B fuses with test light connected to ground. Does test light illuminate for all fuses? If yes, go to step  8. If no, go to step  10.
  6. Turn OFF the ignition. Disconnect negative battery cable. Disconnect underhood fuse block electrical connectors. Test Ignition 1 voltage circuit of ignition relay at underhood fuse block electrical connector for an open circuit or for a short to ground. Did you find and correct the condition? If yes, go to step  11. If no, go to step  10.
  7. Turn OFF the ignition. Disconnect negative battery cable. Disconnect underhood fuse block electrical connectors. Test coil ground circuit of ignition relay at underhood fuse block electrical connector for a high resistance or for an open circuit. Did you find and correct the condition? If yes, go to step  11. If no, go to step  10.
  8. Inspect for poor terminal contact at ignition relay underhood electrical center connector. Did you find and correct condition? If yes, go to step  10. If no, go to next step.
  9. Replace ignition relay. After repairs, go to step  11.
    10. NOTE: DO NOT dissemble or attempt any repairs to underhood fuse block.
  10. Replace underhood electrical center. After repairs, go to next step.
  11. Clear DTCs with scan tool. Turn ignition OFF for 30 seconds. Start engine. Operate vehicle for 5 minutes. Does vehicle operate normally, with no MIL illumination and no stored DTCs? If yes, system is okay. If no, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 8.1L "C", "G" & "K" SERIES TRUCKS article.
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