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Test 5: No Codes

  1. Continuity Check (STI)

    Disconnect positive battery cable. Disconnect ISC-E processor. Set VOM on 200 ohm scale. Measure resistance between processor connector Pin 16 and Self-Test Input (STI) connector. Resistance should be less than 5 ohms. If resistance is less than 5 ohms, go to next step. If not, service harness and repeat quick test.
  2. Continuity Check (STO)

    Set VOM on 200 ohm scale. Measure resistance between processor connector Pin 18 and Self-Test Output (STO) connector. Resistance should be less than 5 ohms. If resistance is less than 5 ohms, go to next step. If not, service harness and repeat quick test.
    Fig 1: Self Test Connector
    G10652
  3. Continuity Check (GROUND)

    Set VOM on 200 ohm scale. Measure resistance between negative battery cable and Self-Test ground connector. Resistance should be less than 5 ohms. If resistance is less than 5 ohms, go to next step. If not, service harness and repeat quick test.
  4. Continuity Check (GROUND)

    Set VOM on 200 ohm scale. Measure resistance between negative battery cable and processor connector Pin 24. Resistance should be less than 5 ohms. If resistance is less than 5 ohms, go to next step. If not, service harness and repeat quick test.
  5. Continuity Check (POWER)

    Set VOM on 200 ohm scale. Measure resistance between positive battery cable and processor connector Pin 1. Resistance should be less than 5 ohms. If resistance is less than 5 ohms, go to next step. If not, service harness and repeat quick test.
  6. Continuity Check (IGNITION RUN)

    Set VOM on 200 ohm scale. Measure resistance from processor connector Pin 14 to ignition run circuit 687. Resistance should be less than 5 ohms. If resistance is less than 5 ohms, replace ISC-E processor and repeat quick test. If not, service harness and repeat quick test.