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Home >> Hummer >> 2009 >> H3 Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 3.7L - DTC P0324 To DTC P0446 >> DTC P0641 or P06A6 >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition OFF, disconnect harness connector of the fuel pressure sensor.
  2. Ignition OFF, test for less than 1.0 ohm between the low reference circuit terminal 2 and ground.
    • If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the FPCM.
  3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
    • If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the FPCM.
    • If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the FPCM.
  4. If all circuits test normal, replace the fuel pressure sensor.