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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 145 (Engine Control System & Fuel - 4.8L, 5.3L, 6.0L And 6.2L - DTC P0335 To DTC P3449) >> DTC P0443 or P0449 >> Circuit/System Testing

Circuit/System Testing

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P0443

  1. Ignition OFF, disconnect the harness connector at the EVAP canister purge solenoid valve.
  2. Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal A and ground.
    • If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply circuit fuse is open, test or replace the EVAP canister purge solenoid.
  3. Connect a test lamp between the voltage supply circuit terminal A and the control circuit terminal B.
  4. Command the solenoid to 50 percent with a scan tool. The test lamp should flash or illuminate when commanded to 50 percent and turn OFF when commanded to 0 percent.
    • If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the control module.
    • If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the control module.
  5. If all circuits test normal, replace the EVAP canister purge solenoid valve.

P0449

  1. Ignition OFF, disconnect the harness connector at the EVAP canister vent solenoid valve.
  2. Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal A and ground.
    • If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply circuit fuse is open, test or replace the EVAP canister vent solenoid.
  3. Connect a test lamp between the voltage supply circuit terminal A and the control circuit terminal B.
  4. Command the solenoid ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between states.
    • If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the control module.
    • If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the control module.
  5. If all circuits test normal, replace the EVAP canister vent solenoid valve.