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Home >> Hummer >> 2009 >> H3 Base, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls And Fuel - 3.7L - DTC P1400 To DTC P2635 >> DTC P1682 >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition OFF, disconnect the powertrain relay.
  2. Ignition ON, verify that a test lamp does not illuminate between the powertrain relay controlled output circuit terminal and ground.
    • If the test lamp illuminates, test the powertrain relay controlled output circuit for a short to voltage.
  3. Ignition OFF, verify that a test lamp illuminates between the powertrain relay coil voltage supply circuit terminal and ground.
    • If the test lamp does not illuminate, test the powertrain relay coil voltage supply circuit for a short to ground or an open/high resistance.
  4. Verify that a test lamp illuminates between the powertrain relay switch voltage supply circuit terminal and ground.
    • If the test lamp does not illuminate, test the powertrain relay switch voltage supply circuit for an open/high resistance.
  5. Disconnect the ECM.
  6. Ignition ON, verify that a test lamp illuminates between ECM connector terminal 19 X1 and ground.
    • If the test lamp does not illuminate, test the RUN/CRNK Relay controlled output circuit for a short to ground or open/high resistance. If the circuit tests normal and its fuse is open, replace the ECM.
  7. Ignition OFF, connect the harness connector at the ECM.
  8. Ignition ON, connect a jumper wire between the powertrain relay voltage supply circuit terminal and the powertrain relay controlled output circuit terminal. Verify the EC Ignition Relay Feedback parameter indicates battery positive voltage.
    • If not the specified value, test the powertrain relay controlled output circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, replace the ECM.
  9. If all circuits test normal, replace the powertrain relay.
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