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Home >> Hyundai >> 2004 >> Accent Base >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System Diagnosis (1 Of 2) >> DTC Troubleshooting Procedures >> DTC P0140: O2 Sensor Circuit No Activity Detected (Bank1/Sensor2) >> Signal Circuit Inspection
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Signal Circuit Inspection

  1. Check for open in harness (signal)
    1. Check for open in harness (signal)
    2. Disconnect HO2S sensor connector.
    3. Ignition "ON" & Engine "OFF"
    4. Measure voltage between terminal 2 of sensor harness connector and chassis ground.

      Specification: approximately 0.45V

      Fig 1: Measuring Voltage Between Terminal 2 Of Sensor Harness Connector And Chassis Ground
      G03851821Courtesy of HYUNDAI MOTOR CO.
    5. Is measure voltage within Specification?

      YES 

      • Go to "Check for open in harness (ground)" below.

      NO 

      • Open circuit between HO2S harness connector and PCM harness connector.
      • Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  2. Check for open in harness (ground)
    1. Ignition "OFF"
    2. Disconnect HO2S sensor connector and PCM connector.
    3. Ignition "ON" & Engine "OFF"
    4. Measure resistance between terminal 1 of sensor harness connector and PCM harness connector.

      Specification: below 1Ω

      Fig 2: Measuring Resistance Between Terminal 1 Of Sensor Harness Connector And PCM Harness Connector
      G03851822Courtesy of HYUNDAI MOTOR CO.
    5. Is measure resistance within Specification?

      YES 

      NO 

      • Open circuit between HO2S harness connector and PCM harness connector.
      • Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.