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Home >> Pontiac >> 2002 >> Aztek AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Ignition System >> Electronic Ignition System Diagnosis (2.2L) >> 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 - 2.2L SONOMA & S10 PICKUP article. After performing Diagnostic System Check - Engine Controls, go to next step.
  2. Crank engine. Observe CKP Activity Counter on scan tool. Does CKP Activity Counter increment? If yes, go to next step. If no, go to step  6.
  3. Remove fuel pump relay with Relay Puller Pliers (J 43244). Install Spark Tester (J 26792) on cylinder No. 1 spark plug wire. Leave other 3 ignition wires connected. Crank engine and observe spark tester for spark. Repeat procedure on cylinders No. 2, 3, and 4. Do all of cylinders have spark? If yes, go to next step. If no, go to step  10.
  4. Turn off ignition. Inspect for malfunctioning spark plugs. If a problem is found, repair condition as necessary. Did you find and correct condition? If yes, go to step  22. If no, go to next step.
  5. Inspect for basic engine problems. Did you find and correct any conditions? If yes, go to step  22. If no, see DIAGNOSTIC AIDS .
  6. Turn OFF the ignition. Disconnect ICM 2-pin connector. Turn on the ignition, with the engine off. Connect a DMM between ICM ground circuit and ICM Ignition 1 voltage circuit at connector. Does voltage measure battery voltage? If yes, go to next step. If no, go to step  17.
  7. Disconnect ICM 6-pin connector. Measure resistance between CKP sensor 1 signal circuit and CKP low reference circuit at connector. Does resistance measure 700-1350 ohms? If yes, go to next step. If no, go to step  11.
  8. With DMM still connected and set to DC Hz scale. Crank engine and observe DMM. Does frequency measure 28-32 Hz? If yes, go to next step. If no, go to step  18.
  9. Connect test light to battery voltage. Momentarily touch test light to low resolution engine speed signal circuit, then touch low reference circuit. Observe CKP Activity Counter on scan tool. Does CKP Activity Counter increment? If yes, go to step  13. If no, go to step  15.
  10. Turn off the ignition. Disconnect PCM connectors. Connect (J 26792) to cylinder No. 1 spark plug wire, and (J 26792) to cylinder No. 2 spark plug wire. Turn on the ignition. DO NOT leave jumper wire connected to PCM IC circuit connector for longer than 5 seconds at a time. Failure to do so may damage ignition coil and/or ignition control module. Connect test light to battery voltage and momentarily touch both IC circuits at PCM connector with test light. Does spark tester spark on both wires? If yes, go to step  14. If no, go to step  16.
  11. Inspect/Test CKP sensor 1 signal circuit for following conditions:
    • Faulty connection.
    • Open circuit.
    • Short to ground.
    • Short to voltage.

    If a problem is found, repair condition as necessary. Did you find and correct condition? If yes, go to step  22. If no, go to next step.

  12. Inspect/Test CKP sensor 1 low reference circuit for following conditions:
    • Faulty connection.
    • Open circuit.
    • Short to ground.
    • Short to voltage.

    If a problem is found, repair condition as necessary. Did you find and correct condition? If yes, go to step  22. If no, go to step  18.

  13. Inspect for faulty connections at ICM. If a problem is found, repair condition as necessary. Did you find and correct condition? If yes, go to step  22. If no, go to step  19.
  14. Inspect for faulty connections at PCM. If a problem is found, repair condition as necessary. Did you find and correct condition? If yes, go to step  22. If no, go to step  21.
  15. Inspect/Test low resolution engine speed circuit for following conditions:
    • Faulty connection.
    • Open.
    • Short to ground.
    • Short to voltage.

    If a problem is found, repair condition as necessary. Did you find and correct condition? If yes, go to step  22. If no, go to step  21.

  16. Test affected IC timing Control circuit for an open or a short. If a problem is found, repair condition as necessary. Did you find and correct condition? If yes, go to step  22. If no, go to step  20.
  17. Repair open in battery voltage and/or ground circuit. After repairs, go to step  22.
  18. Replace CKP sensor. After repairs, go to step  22.
  19. Replace ICM. After repairs, go to step  22.
  20. Replace affected ignition coil. After repairs, go to step  22.
  21. Replace PCM. Program replacement PCM. See POWERTRAIN CONTROL MODULE under PROGRAMMING in SELF-DIAGNOSTICS - 2.2L SONOMA & S10 PICKUP article. After repairs, go to next step.
  22. Turn ignition OFF for 30 seconds. Start engine and operate vehicle. Observe MIL, vehicle performance, and driveability. Does vehicle operate normally, with no MIL illumination and no stored DTCs? If yes, system is okay. If no, go to step  1.
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