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Home >> Suzuki >> 2008 >> XL7 Base, AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine General Information And Diagnosis >> Diagnostic Information and Procedures >> 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, test for B+ on the HO2S ignition voltage circuit terminal C of the HO2S harness connector.
    • If less than the specified value, repair the ignition voltage circuit for an open/high resistance.
  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 with bright intensity.
    • 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 the scan tool HO2S voltage parameter is between 350-500 mV.
    • If less than the specified value, test the signal circuit for a short to ground. If the circuit/connections test normal, replace the ECM.
    • If greater than the specified value, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
  6. Install 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 value, 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 value, 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:
  9. If all circuits/connections test normal, replace the applicable HO2S.
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