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Home >> Buick >> 2006 >> Lucerne CXS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 4.6L - DTC P0016 To DTC P0401 >> DTC P0230 >> Circuit/System Testing
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Circuit/System Testing

  1. With the ignition OFF, remove the fuel pump relay from the rear electrical center using the J 43244  .
  2. With the ignition ON, engine OFF, probe the control circuit of the fuel pump relay with a test lamp that is connected to a good ground. Command the fuel pump relay ON and OFF with a scan tool. The test lamp should turn ON and OFF with each command.
    • If the test lamp does not turn ON and OFF, test for an open or a short to ground in the fuel pump relay control circuit or an intermittent or a poor connection at the engine control module (ECM). If the circuit tests normal, replace the control module.
    • If the test lamp remains illuminated with each command, test for a short to voltage in the control circuit of the fuel pump relay or an intermittent or a poor connection at the ECM. If the circuit tests normal, replace the control module.
  3. Connect a test lamp between the control circuit of the fuel pump relay and the ground circuit of the fuel pump relay. Command the fuel pump relay ON and OFF with a scan tool.
    • If the test lamp does not turn ON and OFF, repair the open or the high resistance in the ground circuit of the fuel pump relay.
    • If the test lamp does turn ON and OFF, test for an intermittent and for a poor connection at the fuel pump relay or a faulty fuel pump relay.
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