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Home >> Hummer >> 2007 >> H3 Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 3.7L - DTC P0013 To DTC P0171 >> DTC P0030, P0036, P0135 or P0141 >> Circuit/System Testing

Circuit/System Testing

  1. With the ignition ON, the engine OFF and the sensor disconnected, connect a test lamp between the HO2S heater supply voltage circuit terminal D and ground. The lamp should illuminate.
  2. With the ignition OFF, connect a test lamp between the HO2S low control circuit terminal E and battery voltage. The lamp should not illuminate.
    • If the lamp illuminates then test the low control circuit for a short to ground. If the circuit tests normal, replace the PCM.
  3. With the engine RUNNING, leave the test lamp connected from the previous step. The lamp should flash or be ON steady.
    • If the test lamp is not ON steady or flashing, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM.
  4. Test for less than 5 ohms resistance in the HO2S heater voltage supply circuit and the low control circuit.
    • If the control module and all circuits test normal, replace the HO2S.
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