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Home >> Chevrolet >> 2009 >> Chevy Express G2500, Van Cargo Extended, 6.6 6 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Fuel System - 6.6L LMM - DTC P0016 To DTC P02E0 >> DTC P0102 or P0103 >> Circuit/System Testing

Circuit/System Testing

  1. Verify the integrity of the entire air induction system by inspecting for the following conditions:
    • Damaged components
    • Loose or improper installation
    • Restrictions or leaks in the air induction system
    • Water intrusion
    • In cold climates, inspect for any snow or ice build-up at the air cleaner and MAF sensor.
  2. Ignition OFF, disconnect the harness connector at the MAF/IAT sensor.
  3. Ignition OFF and scan tool disconnected for 90 seconds, test for less than 5 ohms between the MAF low reference circuit terminal 2 and ground.
    • If greater than the specified range, test the MAF low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Ignition OFF and scan tool disconnected for 90 seconds, test for less than 5 ohms between the IAT sensor 1 low reference circuit terminal 4 and ground.
    • If greater than the specified range, test the IAT sensor 1 low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  5. Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit terminal 3 and ground.
    • If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance.
  6. Ignition ON, test for 4.8-5.2 volts between the MAF signal circuit and ground.
    • If less than the specified range, test the MAF signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    • If greater than the specified range, test the MAF signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  7. Remove the Intake Manifold Tube. Refer to Intake Manifold Tube Replacement (LMM) .
  8. Visually inspect the EGR valve and verify the valve is in the closed position.
    • If the EGR valve is not in the closed position, replace the EGR valve.
    • If the EGR valve inspection is normal, replace the MAF/IAT sensor.
  9. Ignition OFF, connect the red lead of the J 38522  to the signal circuit terminal 1 at the MAF/IAT sensor harness connector. Connect the battery voltage supply to B+. Connect the black lead to ground.
  10. Set the J 38522  signal switch to 5 volts, the frequency to 5K, and the Duty Cycle to Normal.
  11. Engine idling, observe the scan tool MAP sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,025 Hz.
    • If the MAF Sensor parameter is not within the specified range, replace the ECM.
  12. If all circuits and the EGR valve test normal, replace the MAF/IAT sensor.
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