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Home >> Pontiac >> 2009 >> G8 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Fuel System - 3.6L - DTC P0008 To DTC P0277 >> DTC P0134 or P0154 >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
  2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal C and ground.
    • If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.
  3. Ignition OFF, connect a test lamp between the heater control circuit terminal D and B+.
  4. Idle the engine, and verify the test lamp illuminates or flashes.
    • If the test lamp is always OFF, test the control circuit for an open/high resistance. If the circuit/connections test normal, replace the ECM.
  5. Ignition ON, verify that the appropriate scan tool HO2S voltage parameter is between 350-500 mV.
    • If less than the specified range, test the signal circuit for a short to ground. If the circuit/connections test normal, replace the ECM.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
  6. Connect a 3A fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool HO2S voltage parameter is less than 60 mV.
    • If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit/connections test normal, replace the ECM.
  7. Connect a 3A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A. Verify the scan tool HO2S voltage parameter is less than 60 mV.
    • If greater than the specified range, test the low reference circuit for an open/high resistance or for a short to voltage. If the circuit/connections test normal, replace the ECM.
  8. Verify that none of the following conditions exist:
    • The HO2S is loose
    • Lean or rich condition.
    • Water intrusion in the HO2S harness connector
    • Low or high fuel system pressure-Refer to Fuel System Diagnosis .
    • Fuel that is contaminated-Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Fuel saturation of the evaporative emission (EVAP) canister
    • Exhaust leaks near the HO2S
    • Engine vacuum leaks
    • If you find any of the above conditions, repair as necessary.
  9. If all circuits/connections test normal, replace the appropriate HO2S.
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